Release v0.6.43: fix forwarded input and verify snippet pastes

Release v0.6.42: use compact pinned checkbox beside history search
Release v0.6.41: filter and remember pinned clipboard history
2026-11-04 21:18:39 +02:00 · 2026-11-04 20:38:36 +02:00 · 2026-11-04 19:58:15 +02:00 · 2026-11-04 19:45:52 +02:00 · 2026-11-04 19:40:54 +02:00 · 2026-11-04 17:24:57 +02:00
63 changed files with 5946 additions and 382 deletions
@@ -1,14 +1,14 @@
 cmake_minimum_required(VERSION 3.24)
-project(KSwitcher VERSION 0.6.20 LANGUAGES CXX RC)
+project(KSwitcher VERSION 0.6.43 LANGUAGES CXX RC)
 if(NOT WIN32)
  message(FATAL_ERROR "KSwitcher uses native Windows APIs")
 endif()
 set(CMAKE_CXX_STANDARD 20)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
-add_library(kscore src/core.cpp src/platform.cpp src/autostart.cpp src/autocorrect.cpp src/storage.cpp src/ocr.cpp src/richtext.cpp src/update.cpp)
+add_library(kscore src/core.cpp src/platform.cpp src/autostart.cpp src/autocorrect.cpp src/storage.cpp src/ocr.cpp src/richtext.cpp src/update.cpp src/sync.cpp)
 target_include_directories(kscore PUBLIC src PRIVATE vendor)
 target_compile_definitions(kscore PUBLIC UNICODE _UNICODE WIN32_LEAN_AND_MEAN NOMINMAX _WIN32_WINNT=0x0A00)
-target_link_libraries(kscore PUBLIC user32 shell32 shlwapi advapi32 crypt32 imm32 comctl32 gdi32 ole32 oleaut32 taskschd comdlg32 uuid windowscodecs runtimeobject uiautomationcore)
+target_link_libraries(kscore PUBLIC winhttp user32 shell32 shlwapi advapi32 crypt32 imm32 comctl32 gdi32 ole32 oleaut32 taskschd comdlg32 uuid windowscodecs runtimeobject uiautomationcore)
 add_executable(KSwitcher WIN32 src/main.cpp src/app.cpp src/screenshot_notifications.cpp src/screenshot_launcher.cpp src/screenshot_activation.cpp src/configuration.cpp src/ui.cpp resources/app.rc)
 target_compile_definitions(KSwitcher PRIVATE KS_RESIDENT_APP)
 target_link_libraries(KSwitcher PRIVATE kscore)
@@ -17,6 +17,14 @@ set_target_properties(KSwitcherConfig PROPERTIES OUTPUT_NAME "KSwitcher.Config")
 target_compile_definitions(KSwitcherConfig PRIVATE KS_CONFIG_APP)
 target_link_libraries(KSwitcherConfig PRIVATE kscore)
 add_executable(KSwitcherTests tests/tests.cpp)
+add_executable(KSwitcherSyncTests tests/sync.cpp)
+target_include_directories(KSwitcherSyncTests PRIVATE vendor)
+target_link_libraries(KSwitcherSyncTests PRIVATE kscore)
+if(MSVC)
+  set_property(TARGET KSwitcherSyncTests PROPERTY MSVC_RUNTIME_LIBRARY "MultiThreaded$<$<CONFIG:Debug>:Debug>")
+else()
+  target_link_options(KSwitcherSyncTests PRIVATE -static -static-libgcc -static-libstdc++)
+endif()
 add_executable(KSwitcherScrollTests tests/scroll.cpp)
 target_link_libraries(KSwitcherScrollTests PRIVATE kscore)
 target_link_libraries(KSwitcherTests PRIVATE kscore)
@@ -40,6 +48,7 @@ else()
 endif()
 add_executable(KSwitcherOcrTests tests/ocr.cpp src/screenshot_launcher.cpp src/screenshot_activation.cpp src/app.cpp src/screenshot_notifications.cpp src/screenshot.cpp src/configuration.cpp src/ui.cpp resources/app.rc)
 target_link_libraries(KSwitcherOcrTests PRIVATE kscore)
+add_dependencies(KSwitcherOcrTests KSwitcherScreenshot)
 if(MSVC)
  set_property(TARGET kscore KSwitcher KSwitcherConfig KSwitcherScreenshot KSwitcherTests KSwitcherScrollTests KSwitcherIntegration KSwitcherInputTests KSwitcherOcrTests PROPERTY MSVC_RUNTIME_LIBRARY "MultiThreaded$<$<CONFIG:Debug>:Debug>")
  target_compile_options(kscore PRIVATE /W4 /utf-8)
@@ -57,10 +66,55 @@ else()
  target_link_options(KSwitcherOcrTests PRIVATE -static -static-libgcc -static-libstdc++)
 endif()
 enable_testing()
+add_executable(KSwitcherHistoryHostTests tests/history_host.cpp)
+target_link_libraries(KSwitcherHistoryHostTests PRIVATE kscore psapi)
+set_target_properties(KSwitcherHistoryHostTests PROPERTIES RUNTIME_OUTPUT_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}/history-host-fixture-$<CONFIG>")
+add_dependencies(KSwitcherHistoryHostTests KSwitcher KSwitcherScreenshot)
+add_custom_command(TARGET KSwitcherHistoryHostTests POST_BUILD
+  COMMAND ${CMAKE_COMMAND} -E copy "$<TARGET_FILE:KSwitcher>" "$<TARGET_FILE_DIR:KSwitcherHistoryHostTests>/KSwitcher.exe"
+  COMMAND ${CMAKE_COMMAND} -E copy "$<TARGET_FILE:KSwitcherScreenshot>" "$<TARGET_FILE_DIR:KSwitcherHistoryHostTests>/KSwitcher.Screenshot.exe"
+  COMMAND ${CMAKE_COMMAND} -E touch "$<TARGET_FILE_DIR:KSwitcherHistoryHostTests>/.local-dev")
+if(MSVC)
+  target_compile_options(KSwitcherHistoryHostTests PRIVATE /utf-8)
+  set_property(TARGET KSwitcherHistoryHostTests PROPERTY MSVC_RUNTIME_LIBRARY "MultiThreaded$<$<CONFIG:Debug>:Debug>")
+else()
+  target_link_options(KSwitcherHistoryHostTests PRIVATE -static -static-libgcc -static-libstdc++)
+endif()
+add_executable(KSwitcherClipboardSnapshotTests tests/clipboard_snapshot.cpp)
+target_link_libraries(KSwitcherClipboardSnapshotTests PRIVATE kscore psapi)
+add_dependencies(KSwitcherClipboardSnapshotTests KSwitcherScreenshot)
+if(MSVC)
+  target_compile_options(KSwitcherClipboardSnapshotTests PRIVATE /utf-8)
+  set_property(TARGET KSwitcherClipboardSnapshotTests PROPERTY MSVC_RUNTIME_LIBRARY "MultiThreaded$<$<CONFIG:Debug>:Debug>")
+else()
+  target_link_options(KSwitcherClipboardSnapshotTests PRIVATE -static -static-libgcc -static-libstdc++)
+endif()
+add_executable(KSwitcherImageCaptureTests tests/image_capture.cpp)
+target_link_libraries(KSwitcherImageCaptureTests PRIVATE kscore)
+add_dependencies(KSwitcherImageCaptureTests KSwitcherScreenshot)
+if(MSVC)
+  target_compile_options(KSwitcherImageCaptureTests PRIVATE /utf-8)
+  set_property(TARGET KSwitcherImageCaptureTests PROPERTY MSVC_RUNTIME_LIBRARY "MultiThreaded$<$<CONFIG:Debug>:Debug>")
+else()
+  target_link_options(KSwitcherImageCaptureTests PRIVATE -static -static-libgcc -static-libstdc++)
+endif()
+# Explicit interactive test: stop the resident first so its clipboard listener
+# does not capture the test fixtures. Like KSwitcherIntegration, not part of ctest.
+add_executable(KSwitcherDictionaryTests tests/dictionary.cpp)
+target_link_libraries(KSwitcherDictionaryTests PRIVATE kscore psapi)
+if(MSVC)
+  set_property(TARGET KSwitcherDictionaryTests PROPERTY MSVC_RUNTIME_LIBRARY "MultiThreaded$<$<CONFIG:Debug>:Debug>")
+else()
+  target_link_options(KSwitcherDictionaryTests PRIVATE -static -static-libgcc -static-libstdc++)
+endif()
+add_test(NAME dictionary-regressions COMMAND KSwitcherDictionaryTests)
+set_tests_properties(dictionary-regressions PROPERTIES WORKING_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}")
+add_test(NAME sync-regressions COMMAND KSwitcherSyncTests)
 add_test(NAME native-regressions COMMAND KSwitcherTests)
 add_test(NAME scroll-regressions COMMAND KSwitcherScrollTests)
 add_test(NAME input-regressions COMMAND KSwitcherInputTests)
 add_test(NAME screenshot-ui-regressions COMMAND KSwitcherScreenshotUITests)
+add_test(NAME screenshot-save-regressions COMMAND KSwitcherScreenshotUITests --save-only)
 add_test(NAME updater-regressions COMMAND powershell.exe -NoProfile -ExecutionPolicy Bypass -File "${CMAKE_CURRENT_SOURCE_DIR}/tests/update.ps1" -Executable "$<TARGET_FILE:KSwitcher>")
 set_tests_properties(native-regressions PROPERTIES WORKING_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}")
 install(TARGETS KSwitcher KSwitcherConfig KSwitcherScreenshot RUNTIME DESTINATION .)
@@ -16,6 +16,16 @@ Run `build/KSwitcher.exe`, or extract `dist/KSwitcher-win-x64.zip` and run the e
 The build also refreshes the release copy in `build/release/`. Exit KSwitcher before rebuilding.
 The application lives in the notification area. Right-click its icon for Settings, Snippets and history.
 Double-click the tray icon to open Settings, the bold default menu item.
+Closing Settings with unsaved changes (including accepted auto-correction or OCR options)
+asks whether to save, discard changes, or keep editing. Unchanged settings close without a prompt.
+If saving fails, the window stays open with your edits intact.
+Menus support access keys: press the underlined letter while the menu is open (for example,
+S for Settings or X for Exit in the tray menu). In forms, press Alt+the underlined letter
+to activate a button, toggle a checkbox or focus a labeled field. Dialog underline visibility
+still follows Windows preferences; press Alt in a dialog to reveal them.
+From v0.6.33, tray and history menus show access letters in the right-hand column.
+Press the menu letter without Alt: Alt dismisses an open menu. Shortcut-capture fields still record Alt combinations;
+press Tab to leave a shortcut field before using form access keys.
 Settings, the snippet editor and log viewer run on demand in **KSwitcher.Config.exe**, beside the main executable.
 Repeated launches activate the existing configurator; closing its last window exits that process.
 Saving applies changes immediately through the resident KSwitcher process. The configurator does not
@@ -65,6 +75,9 @@ Ctrl+Alt+Delete and Win+L; these cannot be assigned.

 Keyboard and mouse input forwarded by Microsoft Mouse Without Borders follows the same input
 path as a local keyboard/mouse, including shortcuts, recent-word conversion and snippets.
+On the sending computer, KSwitcher ignores keyboard events consumed by another keyboard hook
+(including Mouse Without Borders forwarding). The receiving computer still processes delivered
+input normally, so both computers can run KSwitcher without starting duplicate snippet operations.
 KSwitcher marks its own generated input so copy/paste, selection, modifier releases and shell-mask
 keys cannot trigger recursive commands or overwrite the recorded typing run. Other injected input
 is accepted, including key-up events and VK-only keyboard events. Unicode packets do not provide
@@ -90,6 +103,10 @@ broker can load them even when the profile directory is inaccessible to it.
 Notifications expire after 24 hours. Cache cleanup runs on capture/open; each cache is bounded to
 40 files and 256 MiB. Expired or evicted notifications cannot reopen their screenshot.
 In the editor, **Ctrl+C** or **Enter** copies the current result without closing the window.
+**Save… / Ctrl+S** saves the full-resolution image and annotations as PNG. The first save asks
+for a file; later saves update that file. **Ctrl+Shift+S (Save As…)** always asks for a new
+destination. Saving keeps the editor open and leaves the clipboard unchanged. Further edits
+must be saved or copied again before closing without a warning.
 The editor starts with **Pencil / Freehand (F)** for drawing. Choose **Pointer (V)** to select objects, move them, and edit geometry, thickness and
 other properties using handles and controls. Clicking empty space clears selection; dragging empty
 space adds nothing. Choose a drawing tool to create objects, then return to **V** to edit them.
@@ -107,10 +124,10 @@ change its diameter. Wheel up increases the size; wheel down decreases it. These
 and update linked arrows. **Ctrl+D** clones the selected object with a small offset. A cloned number
 gets the smallest available positive number, just like a newly placed number: gaps left by deletion
 are filled first, without renumbering existing objects. A cloned arrow keeps its style but starts without endpoint links.
-Arrow and line endpoints can attach to numbered markers, rectangles, circles, ellipses, text blocks,
+Arrow and line endpoints can attach to numbered markers, rectangles, circles, ellipses, triangles, trapezoids, text blocks,
 and other arrows or strokes. In Arrow or Straight line mode, hold **Ctrl** and drag from one object
 to another to draw over them and automatically attach both endpoints. Without Ctrl, existing objects
-can still be selected and edited as before. With Pointer, drag an existing endpoint onto a target to attach it. Attached endpoints follow movement and resizing; text attachments
+can still be selected and edited as before. With Pointer, drag an existing endpoint onto a target to attach it. Attached endpoints follow movement and resizing; shape and text attachments
 also follow rotation. Arrow-to-arrow attachments retain their relative position along the target line.
 Clicking a connector or adding/editing its caption preserves its links. Moving the whole connector
 intentionally detaches its endpoints; moving one endpoint detaches only that end. Deleting a target
@@ -158,7 +175,41 @@ resize; circles keep equal width and height. Move shapes by their outlines, adju
 the mouse wheel or side handle, recolor, clone with Ctrl+D, and undo/redo as with other objects.
 Hold Ctrl to start drawing over an existing object. Line style applies to outlines; Ends is disabled
 for shapes.
+**Canvas zoom:** use **Ctrl++ / Ctrl+-** (including numpad keys) or **Ctrl+mouse wheel**.
+Each step changes the view by 25%; the wheel zooms around the cursor, keyboard shortcuts around
+the viewport center. **Ctrl+0** restores the initial fit. Drag with the **middle mouse button**
+to pan an enlarged image. Panning is limited to axes where the image exceeds the viewport;
+an image that fits stays centered. Zoom ranges from 0.1× to 16× the initial fit; the status bar shows the
+actual image scale. Zoom and pan do not change annotations, export resolution or undo history.
+The wheel without Ctrl still adjusts the object under the cursor.
+
 **Freehand line (F)** draws an opaque curve by following the mouse. The curve is one object:
+after mouse release, nearly straight strokes become editable straight lines at their drawn angle,
+preserving endpoints, color, thickness, line style and arrowheads. Short strokes, broad curves and
+retraced strokes are not straightened. Other strokes receive light smoothing to reduce jitter.
+Confidently recognized closed outlines become
+rectangles, circles, ellipses, triangles or trapezoids (including tilted outlines), stored as shape objects.
+Drag either bounding-box corner handle to resize the entire recognized outline; circles keep equal
+width and height. Shapes can also be moved, recolored and cloned.
+Every shape has a round rotation handle above its outline. Drag it to rotate around the center;
+hold **Shift** for 15-degree steps. The handle works for toolbar shapes and recognized shapes,
+including triangles. Resize handles and attached connectors follow the rotation; Ctrl+Z/Ctrl+Y
+undo and redo it. The square handle still controls outline thickness.
+From v0.6.34, endpoint, shape-corner and number-radius handles show the four-direction move cursor.
+Thickness handles retain directional resize cursors; rotation retains the hand cursor. Dragging,
+snapping and shape constraints are unchanged.
+**Triangle (G)** is also available directly on the toolbar: drag to create a triangle.
+Both drawn and recognized triangles have three independent vertex handles instead of bounding-box
+resize handles. Drag any vertex to reshape the triangle while keeping the other two fixed, even
+after rotation. Vertex edits support undo/redo, and the rotation and thickness handles remain available.
+**Trapezoid (B)** on the toolbar creates a trapezoid with parallel bases. Pencil recognition also
+fits nearly parallel, unequal bases into a clean trapezoid. Trapezoids support bounding-box resizing,
+rotation, styling and undo/redo; Ctrl+Z after recognition restores the original pencil stroke.
+Oval fitting tolerates uneven contours and small closing gaps or overlaps; broad open arcs and
+repeated loops remain freehand strokes.
+Press **Ctrl+Z** once to restore the original stroke, again to remove it; **Ctrl+Y** reapplies the improvement.
+Small strokes, strokes linked to other objects, and any stroke drawn partly with Shift are left unchanged.
+Ambiguous shapes are only smoothed. To edit the resulting curve,
 move it, change its color or thickness, clone it, or drag its endpoints. Hold Ctrl to start a new
 stroke over an existing object. Hold **Shift** while drawing to constrain the current segment
 to a horizontal, vertical or 45-degree diagonal line; release Shift to resume freehand drawing in the same stroke.
@@ -168,7 +219,7 @@ released repeatedly within one stroke. The **Line style** selector supports Soli
 Dash-dot; **Ends** supports an arrow at the end, start, both ends, or no arrows. These settings
 apply to selected straight/freehand lines and set defaults for subsequent lines. Both are disabled
 for numbered markers and highlights unless a line drawing tool is active. Undo/Redo includes style changes.
-The window close button asks for confirmation before discarding an uncopied screenshot.
+The window close button asks for confirmation before discarding changes that have not been saved or copied.
 **Escape** cancels region selection or inline text edits; it does not close the editor. Copy keeps the editor open and publishes the image
 at its original pixel size, ready to paste. The preview fits the window without changing export size.
 The shortcut is configurable in Settings under **Screen capture**.
@@ -220,15 +271,31 @@ thumbnails and source labels aligned with the scaled fonts and spacing.
 ## Implemented

 - Installed Windows keyboard layouts, configurable cycle/order and direct shortcuts; IMEs are switch-only.
+  Text conversion cycles skip layouts that leave the text unchanged and use the next enabled layout
+  that changes it. If none changes the text, the operation keeps the text and advances one layout.
+  Partial copied suffixes can be reselected with paced keys; replacement still requires verification
+  of the complete expected text. Browser/editor compatibility depends on its handling of simulated input.
 - Selection conversion and verified recent input (physical scan codes, 2-second typing-run boundary).
 - Same-process clipboard ownership plus verified WebView2 descendants, including the Teams fix.
+  Clipboard synchronizers such as Mouse Without Borders may republish a copy only when
+  KSwitcher first observed it owned by the target application and the selection text and
+  editor selection metadata remain identical. Unobserved or altered foreign copies are rejected.
+  Snippets require accessibility verification of their selected trigger and pasted text,
+  even with logging disabled. If verification is unavailable or the paste differs, expansion
+  stops without running cursor or Enter actions. Clipboard changes during paste also cancel actions.
 - Teams recent-word conversion uses a single word-selection command and validates the copied range.
  If the editor's word boundary differs from the recorded typing, it falls back to paced character
  selection: Teams can coalesce a burst of Shift+Left events into just one character.
 - Clipboard snapshot/restoration with concurrent-copy, foreground and input-version checks.
+  A snapshot interrupted by a concurrent clipboard publication is retried up to three total
+  attempts before selection starts, provided the foreground and input context remain unchanged.
  A silently dropped copy is retried up to three total attempts while the clipboard and input
  context remain unchanged. Temporary transaction contents are excluded from Windows clipboard
-  history and cloud synchronization. Paste is not blindly retried.
+  history and cloud synchronization. Paste is not blindly retried: with manual paste readback
+  enabled by Write log, a native Windows EDIT gets at most one retry when readback reports the
+  original and fresh native queries confirm that exactly the original range is still selected.
+  Other controls and unknown/changed selections are not retried. A verified failed paste clears
+  repeat-conversion state and does not switch the Windows layout.
 - Case cycling, Russian/Ukrainian transliteration, verified undo and repeated conversion.
 - Text snippets across layouts, multiline insertion and a verified `{cursor}` position;
  `{enter}` presses Enter after insertion and cursor placement (once per marker), before buffered typing resumes.
@@ -278,21 +345,16 @@ existing saved shortcuts are preserved. While KSwitcher runs, this binding opens

 History controls: Enter to paste, Shift+Enter for plain text, Ctrl+1…9 for quick paste,
 Ctrl+P to pin/unpin, Delete to delete, Ctrl+O for the full item, Escape to hide.
+
+**Clear history… / Alt+H** in the history window clears all saved entries after confirmation,
+including pinned entries and entries hidden by search. No is the default choice. The current
+Windows clipboard and future recording are unchanged. Settings also retains its Clear history action.
 For an image, **Edit image**, **Ctrl+O**, or **Edit image in screenshot editor**
 in the context menu opens the original image in the built-in screenshot editor.
 Annotate it there, then copy the result. Opening the editor leaves the
 clipboard and original history entry unchanged. Text items still open as text;
 Enter and double-click still paste the selected item.

-Local builds made with `build.ps1` show **[LOCAL DEV]** in window titles and
-the tray tooltip. The marker is enabled by `.local-dev` beside the executable;
-release packages do not include that marker.
-
-Fast/inertial wheel events use a shared batching handler in history, layout and
-snippet lists, the log table, multiline text/details fields, combo boxes and
-scrollable settings windows. High-resolution partial wheel steps are retained.
-History pauses new preview loads while scrolling and keeps visible thumbnails
-cached, preventing continuous flicker and needless redraws.
 Pressing the history shortcut a second time pastes the second-most-recent item.

 ## Data and migration
@@ -302,7 +364,14 @@ the executable's directory is not writable. Each clipboard payload is an encrypt
 only bounded previews/metadata stay in memory. Image data is loaded on demand and released when
 the history popup is hidden. Settings **Write log** (`writeLog`, enabled by default) controls all
 log writes. Disabling it also clears diagnostic context from memory; existing log files remain.
-Diagnostic stages stay in a memory buffer of at most 40 events for 30 seconds.
+Diagnostic stages stay in a memory buffer of at most 128 events for 30 seconds.
+Selection diagnostics include the expected text, each copied candidate before and after suffix
+recovery, paced Shift+Left progress or batch delivery counts, and clipboard sequence changes,
+retry counts and elapsed times. Focus, caret geometry and keyboard layout are recorded when
+Windows exposes them; selection offsets are available for native EDIT controls and explicitly
+marked unavailable for other editors. Input interruptions identify keyboard, mouse, settings
+or layout-refresh events during an operation. Failed selection verification includes the expected
+selection and actual copied text in the operation details, without implying that a paste occurred.
 Only problem operations write a structured summary to `kswitcher.log`, with their preceding
 context. Successful operations stay in that bounded memory buffer and are included only when
 a subsequent problem flushes it; they do not create separate rows. Flushed context is discarded. Ordinary application
@@ -354,6 +423,119 @@ This is a working native implementation, not a claim of complete UI/release pari
 The Windows focus/injection rules still apply: an unelevated process cannot edit an elevated app.
 Conversion is cancelled rather than pasting into a different window or replacing unverified recent text.

+## OpenBao synchronization (experimental, opt-in)
+
+The **Sync...** button is available in Settings for everyone. Synchronization remains disabled
+until you configure your own OpenBao and enable it. Connection configuration is saved separately
+in `sync.json`. The portable data directory is normally `data/` beside the executable; installations
+without a writable application directory use the existing local-app-data fallback.
+No server address or account is included in the application.
+
+The first provider is **OpenBao KV v2**. The dialog accepts an HTTPS server origin, username,
+password, KV mount (default `kswitcher`), profile path (default `personal/settings`) and userpass
+authentication mount (default `userpass`). Use the same profile on each of your PCs. This is
+administrator-provisioned private access, not public account registration. Non-root namespaces,
+reverse-proxy URL prefixes, MFA login flows and other providers are not implemented yet.
+
+Enable synchronization and choose **Save / Sign in / Sync**. The dialog saves connection changes
+immediately; the main Settings window's Save/Cancel does not control this separate configuration.
+When synchronization is disabled, connection fields and sync actions are inactive. Check **Enable
+synchronization** to make them available. To disable an existing connection, uncheck it and click
+**Save**; this preserves the saved connection and password without starting a sync request.
+**Disconnect / forget password** remains available while synchronization is disabled.
+A blank password keeps the existing Windows credential for that server, login mount and username.
+The password is saved in Windows Credential Manager, not in settings exports, logs or the remote
+profile. HTTPS certificate validation is mandatory and redirects are refused. Login tokens are
+kept in memory for one sync attempt, with best-effort self-revocation afterwards. Configure bounded
+token lifetimes on the server as well (for example a 5-minute default and 10-minute maximum).
+**Disconnect / forget password** disables synchronization and removes the current connection's
+saved credential. A request already sent to the server may still complete; its downloaded settings
+will not be applied after the connection changes. Old credentials for other connection identities
+can be removed in Windows Credential Manager under `KSwitcher.Sync/`.
+
+On the first connection, **Save / Sign in / Sync** merges the existing profiles without
+requiring a whole-profile replacement. Independent entries (such as snippets, exclusions and
+replacement pairs) are combined. Different values for the same setting remain on their respective
+sides and appear in **Resolve individual conflicts...**; no value is guessed without a common history.
+Nonconflicting changes synchronize immediately, and unresolved conflicts survive subsequent syncs.
+
+- **Upload local** creates the remote profile or replaces it with this PC's saved shared settings.
+- **Download remote** replaces this PC's shared settings with the server profile.
+- If the server has no profile yet, choose **Upload local** to create it.
+- Unsaved edits in Settings are not synchronized. Close and reopen Settings after a download;
+  the existing stale-editor check prevents an old Settings window overwriting downloaded changes.
+
+Once connected, the resident checks at startup, every **10 minutes**, and about two seconds after saving settings, on a separate
+network thread. Errors back off for 15 minutes; the Sync button allows a manual retry. Local use
+continues offline. Independent changes to different settings fields are merged against the last
+successful baseline. **Resolve individual conflicts...** shows the name and local/server values
+for each conflict. Choose either value for selected settings and apply your choices; unselected
+conflicts stay pending. Other, nonconflicting changes continue to synchronize. Choices are checked
+against freshly read values before writing, so a stale dialog cannot overwrite a newer edit.
+Conflicting shortcuts are separate settings, including bindings for individual keyboard layouts.
+Exclusions and personal dictionary words merge by membership. Ordered layout/dictionary lists
+remain single settings because their ordering affects behavior.
+
+Snippets have persistent IDs that survive renaming. Different snippets merge independently;
+trigger and text edits within a snippet can merge too. Deleting a snippet retains a deletion
+marker, so an unchanged offline copy cannot bring it back. Deletion versus a concurrent edit
+is an explicit conflict, offering the deleted or edited version. Duplicate triggers and shortcut
+collisions created by independent edits are also presented for resolution. Deletion markers are
+retained without automatic expiry; recreating a snippet in the editor gives it a new ID.
+
+Existing profiles migrate automatically: legacy snippet IDs derive deterministically from the
+original trigger, then are stored permanently. Sync writes use envelope version 2; older clients
+refuse this version instead of dropping IDs/deletions. Update all participating PCs before using
+the new merge behavior. Existing version-1 profiles and local baselines remain readable.
+
+Download/Upload are still available for deliberate whole-profile recovery/initialization, not
+required for ordinary conflicts. Every server write uses the version just read as a CAS
+condition, including explicit Upload. A racing write is rejected rather than silently overwritten.
+Deleted server versions are not silently recreated.
+
+Hotkeys, snippets, application exclusions, layout order, conversion, screenshot and autocorrection
+preferences are shared. Startup/elevation, keep-awake, logging, history enablement/limits,
+Tesseract executable/engine selection, connection details and credentials stay local. Clipboard
+history, screenshots and dictionary files are never uploaded. Full synchronization identifies
+missing keyboard layouts by language (when Windows can identify it) and exact ID.
+Install the same layout variant, or select **Keep this PC's layouts and layout shortcuts (sync
+other settings)** and click **Save / Sign in / Sync**. This device-local option keeps the entire
+local layout cycle and its direct shortcuts unchanged while synchronizing the other shared settings.
+The server's layout cycle and direct shortcuts are preserved on automatic sync and explicit Upload;
+Download also keeps the local layout configuration. Later syncs cannot erase missing server layouts
+just because this PC does not have them installed. Uncheck the option to resume full layout sync.
+Settings are JSON inside OpenBao; this is not end-to-end encryption from the vault administrator.
+
+The last common profile (`sync-base.bin`) and the settings preceding the most recent downloaded
+change (`settings-before-sync.bin`) are protected with Windows DPAPI and belong to this Windows
+account/machine. Reinstallation recovery uses the remote profile and a fresh login; copying these
+local DPAPI files to a new machine does not recover them. For an older server snapshot, use OpenBao
+KV version history to restore that snapshot as the latest version, then choose Download remote.
+The app does not yet provide a server-history browser. Keep ordinary server backups too.
+
+OpenBao administrator setup:
+
+1. Enable a KV **version 2** engine at `kswitcher`; enable **Require Check-and-Set** and set
+   maximum versions to a suitable value, such as 30.
+2. Create a dedicated userpass account, with a policy restricted to the chosen profile. Do not
+   use the administrator account. For the defaults, the application needs only:
+
+   ```hcl
+   path "kswitcher/data/personal/settings" {
+     capabilities = ["create", "read", "update"]
+   }
+   path "auth/token/revoke-self" {
+     capabilities = ["update"]
+   }
+   ```
+
+3. Set bounded token lifetimes on that account/auth mount and enter its credentials in KSwitcher.
+   Keep the server's address and TLS certificate reachable/trusted on each participating PC.
+
+`SyncProvider` separates versioned read/conditional-write operations from merging, local state
+and UI integration, so another service can be added without replacing the synchronization logic.
+Protocol and conflict regressions run with `build.ps1 -Test` or CMake's `sync-regressions` test.
+
 ## Build

 The easiest reproducible local route uses the pinned portable w64devkit toolchain:
@@ -373,13 +555,40 @@ Alternatively open this directory as a CMake project in Visual Studio with the C
 and Windows SDK installed, or use CMake with a Windows GCC toolchain. CMake/MSVC is provided but the
 verified local build uses GCC/w64devkit.

-## Automatic layout correction (experimental)
+## Automatic correction (experimental)

-Enable **Automatically correct layout (experimental)** in Settings, then use **Auto-correction
+Enable **Automatic correction (experimental)** in Settings, then use **Auto-correction
 options…** to select dictionary languages and edit excluded applications or words to never correct.
 The feature is off by default. English and Ukrainian are selected initially; Russian is optional.
 Target layouts must also be enabled in the layout cycle.

+### Custom replacements and spelling typos
+
+Two optional modes in **Auto-correction options…** extend layout correction. Both are off by
+default and require the main **Automatic correction (experimental)** checkbox to be enabled.
+
+- **Use custom replacements**: enter one `typo=correction` pair per line, for example
+  `првиіт=привіт` or `helo=hello`. Entries are normalized to lowercase; duplicate source words
+  are rejected. Each side must contain 1–32 letters of the same supported language, without
+  spaces or punctuation. Explicit pairs take priority over dictionary recognition, including
+  already valid words, and do not require dictionary membership or satisfy the frequency limit.
+- **Correct spelling typos using dictionaries**: checks unknown words in the current language
+  after no layout correction is found. It accepts exactly one dictionary candidate reachable
+  by inserting, deleting or replacing one letter, or swapping two adjacent letters. Both input
+  and target must have at least four letters. Multiple candidates leave the input unchanged,
+  even if a frequency limit would exclude one of them. Personal dictionary words participate.
+  This is word-level spelling correction, not grammar or sentence-context correction.
+
+Both modes run after Space, preserve surrounding punctuation and an initial capital, and keep
+the current layout. The selected dictionary languages, enabled layout cycle, minimum input
+length, excluded applications, never-correct list, protected fields and Undo behavior apply.
+ALL CAPS, mixed-case identifiers, numbers, URLs and email addresses are skipped. A replacement
+is applied once, without chaining. Click **OK**, then **Save** in Settings; pairs and switches
+are included in settings export/import and synchronization. Undo restores the original word
+and suppresses its correction until restart.
+
+### Layout correction and shared options
+
 **Characters before a word** and **Characters after a word** configure punctuation to preserve around
 the corrected word. Enter characters directly, without spaces or separators; a comma or semicolon
 is itself a character. Defaults include parentheses, square/curly brackets, quotation marks and common
@@ -394,6 +603,8 @@ protect already valid input, and ambiguous alternatives remain unchanged regardl
 **My dictionary** provides separate English, Ukrainian and Russian fields for correct words missing
 from the bundled dictionaries. Enter words separated by commas or new lines, then click OK and Save
 in Settings. Case and duplicates are normalized automatically; no file editing or ranks are needed.
+The v0.6.23 bundled Ukrainian dictionary includes `поточні`. The updater preserves existing dictionary files;
+if upgrading from an older dictionary, add this word in My dictionary → Ukrainian and click OK → Save.
 These entries are stored in settings and survive dictionary updates. They protect correct input and
 are eligible as correction targets at any frequency limit. The language and target layout must still
 be enabled. **Never correct these words** is a separate exception list and takes precedence.
@@ -427,7 +638,12 @@ support automatic correction. Dictionary recognition is heuristic, not an unders
 subtitle vocabulary is incomplete, and uncommon names or jargon can need personal exceptions.

 No network service or language model is used. The three dictionary files occupy about 2.6 MB on disk;
-the English/Ukrainian lookup data uses less than 3 MiB of RAM and is loaded on first automatic check.
+the bundled EN/UK/RU lookup payload uses about 0.90 MiB of RAM. When automatic correction is enabled,
+selected dictionaries are loaded before typing and shared by the input predictor and worker.
+Words are stored in compact indexed blocks; all words and frequency ranks are retained, and editable
+UTF-8 dictionary files keep the same format. Custom dictionaries can use more memory.
+`build.ps1 -Test` checks every bundled word/rank and measures lookup speed; CMake exposes the same
+check as `dictionary-regressions`. The payload figure excludes the rest of the process and allocator overhead.
 Keep `dictionaries/` beside the executable when copying the app. These word lists derive from
 [FrequencyWords](https://github.com/hermitdave/FrequencyWords) and are separately licensed under
 CC BY-SA 4.0; attribution, pinned source revision and license are in `dictionaries/`.
@@ -498,3 +714,31 @@ Keep `v0.4.2` as the last legacy `vX.Y.Z` release. Publish full packages as
 legacy version tag: clients that have not installed the bridge would select it.
 Keep the compatibility bridge in the first 100 releases returned by Gitea while
 supporting old clients; their immutable update code only reads that page.
+
+### Editors that omit copied trailing spaces
+
+From v0.6.31, KSwitcher recovers trailing ordinary spaces omitted by Ctrl+C only when Windows accessibility proves the complete selection. The same focused control and range are rechecked before paste, and the result is read back even without Write log. Recent-text conversion, automatic correction, repeat conversion and Undo retain exact verification. Missing letters, tabs, line breaks and unavailable or ambiguous selections are not reconstructed. No setting or shortcut has changed.
+
+### Notification registration and Viber — v0.6.36
+
+Notification registration runs in KSwitcher.Screenshot.exe; keep all three executables together. Startup registration is asynchronous. Viber pastes allow 75 ms for clipboard notifications before Ctrl+V, retaining focus, ownership and selection checks. This mitigates an intermittent clipboard timing issue; it does not guarantee all Viber failures are resolved. UI Automation is unchanged.
+
+### Image history, OCR and duplicate fingerprints — v0.6.37
+
+Image clipboard capture and automatic/uncached manual history OCR run in short-lived KSwitcher.Screenshot.exe processes. Keep all three executables together. Original clipboard formats, image limits, privacy exclusions, Windows OCR, optional Tesseract and searchable encrypted OCR results are preserved. Background OCR is cancelled on shutdown or an OCR-profile change; late results do not recreate deleted entries.
+
+Consecutive duplicates use SHA-256 fingerprints inside the encrypted history index, including pixel fingerprints for equivalent image encodings. Older entries acquire fingerprints on first comparison without a bulk migration. Pins and OCR caches survive duplicate detection; non-consecutive copies still create separate entries. New text no longer loads the preceding image to rule out a duplicate. No shortcut, setting or default changed.
+
+Moving OCR isolates its temporary memory rather than reducing the combined processing peak. A controlled three-run comparison retained about 0.8 MiB less private RAM in the caller after recognition; combined peak RAM was about 55.6 MiB before and 56.6 MiB with the helper. Results depend on the image, OCR engine and system.
+
+### Pinned history checkbox — v0.6.42
+
+Check **★ Pinned only** beside the history search box to show only pinned entries; uncheck it to show all entries. The checkbox sits on the left, immediately followed by the search box; its right edge stays aligned with the history list when resizing. The text search applies within that filter. Unpinning an item removes it from the pinned view immediately. The checkbox state and search are remembered after closing and reopening history. **Clear history…** still deletes the entire history after confirmation, including entries hidden by the filter.
+
+### History process and clipboard memory — v0.6.40
+
+History opens in a separate, short-lived instance of **KSwitcher.exe**. **Esc** closes it even when focus is on the window or an action button, releasing Windows UI allocations with the process. The resident keeps keyboard hooks, clipboard capture and history storage. Search, selection and the top entry are preserved in encrypted view state. If a full-text item viewer is still open, the helper stays alive until the last viewer closes. Pin/delete, formatted/plain paste and OCR remain available; settings and default shortcuts are unchanged.
+
+Image thumbnails are decoded in **KSwitcher.Screenshot.exe**, returning only bounded preview pixels. Image clipboard backup/restore also uses that helper and encrypted temporary files, with clipboard-sequence checks before restoring. Selection reads avoid loading image formats. Keep all three executables together; no fourth executable is required. Paste allows a brief foreground handoff after history closes while preserving cancellation checks. UI Automation remains in the resident.
+
+A live development-build test measured **4.37 MiB before history and 4.35 MiB after two open/Esc cycles**, compared with an earlier roughly 8–9 MiB plateau. A same-image clipboard-backup benchmark retained **12.78 MiB before versus 0.05 MiB after**. These measure private working set, not a guaranteed total footprint. Include all helpers when measuring active use: combined memory can be higher while history is open. No forced working-set trimming is used. Existing screenshots and shortcuts remain applicable. The v0.6.38 approach of retaining a hidden history window/RichEdit control is superseded by process termination.
@@ -1,30 +1,23 @@
 # Latest Windows release

-## v0.6.20 — 2026-10-31
+## v0.6.43 — 2026-11-04

 ## Changes
- Open clipboard-history images in the built-in screenshot editor with **Edit image**, **Ctrl+O**, or **Edit image in screenshot editor** in the context menu. PNG, DIB and DIBV5 open at full resolution through an encrypted local cache, without requiring notifications or changing the clipboard/original history entry. Copy the annotated result explicitly from the editor.
- Fix continuous history flicker by keeping visible previews cached, invalidating only completed preview rows and preserving the top entry across background refreshes.
- Handle fast/inertial wheels through one shared batching mechanism for history, layout/snippet lists, the log table, multiline text/details fields, combo boxes and scrollable settings windows. Preserve partial wheel deltas, clamp list boundaries and pause new history previews until scrolling stops.
- Mark local developer builds with **[LOCAL DEV]** in window titles and the tray tooltip. Release packages omit the development marker. This does not create a separate data profile.
- Right-clicking a history entry selects that entry before showing its actions. Enter and double-click continue to paste; text items still open in the full-text viewer.
+- Respect downstream keyboard-hook suppression before tracking input or starting snippets. This prevents source-side expansion of keys forwarded by Mouse Without Borders. Update KSwitcher on both computers, especially the keyboard-sharing source.
+- Verify snippet selection and pasted text through accessibility even with logging disabled. Unavailable verification, incorrect text or clipboard changes cancel further cursor/Enter actions. No snippet syntax, shortcut or default changed.
+- Accept identical clipboard relays only after observing target-owned content, preserving text and editor selection metadata checks. Unicode allocation padding and format order do not cause false mismatches; changed content remains rejected.
+- Retry clipboard snapshots interrupted by concurrent publication up to three times before selection, while input context remains unchanged.
+- Clicking a warning notification opens Logs. Copy rejection diagnostics include observed/current text, clipboard sequences and the sentinel for troubleshooting.

 ## Validation
-Passed 406 native regressions, 473 input/UI checks, shared wheel batching tests, screenshot editor UI, notification registration, 48 updater checks and updater progress checks. Manual testing confirmed image editing from history and resolved clipboard flicker and Logitech inertial-wheel beeping. Shared wheel tests cover lists, edits, tables, combo boxes and windows, partial steps, large bursts, selection preservation and list boundaries.
+Release regression checks cover dictionary equivalence (140,939 words), 105 sync checks, 319 native checks, 569 input checks, screenshot UI/save/registration, 48 updater checks and updater progress UI. The isolated snippet suite exercises an actual downstream forwarding hook, verifies no source-side copy or text changes, and checks normal expansion, Enter, buffered typing, copy retries and suppression of Enter after incorrect pasted text.

-## Limitations
-Image decoding or a normalized image larger than the 128 MiB editor-transfer limit can prevent opening; an error is shown. Existing clipboard, OCR and editor privilege limitations remain. The wheel over screenshot annotations changes size/thickness rather than scrolling.
+Live two-computer validation with both instances updated remains outstanding. An older instance on either computer can still interfere; the fix does not accept unrelated clipboard contents.

-**Upgrade:** choose Update in the tray menu. Legacy v0.3.0–v0.4.1 clients first receive the v0.4.2 compatibility bridge, then the current full release. v0.2.3 and earlier require manual installation.
-For manual installation, exit KSwitcher, close screenshot editors and extract the entire ZIP into its installation folder. Keep personal `data/` and customized dictionaries.
+## Upgrade
+Choose **Update** in the tray menu on both computers. Legacy v0.3.0–v0.4.1 clients first receive the v0.4.2 compatibility bridge, then the current full release. v0.2.3 and earlier require manual installation.
+For manual installation, exit KSwitcher, close its configurator and screenshot editors, and extract the entire ZIP into its installation folder. Keep personal `data/` and customized dictionaries.

-Download **KSwitcher-win-x64.zip** with **SHA256SUMS.txt**. The package contains all three executables, a release manifest, offline dictionaries, documentation and license notices. It contains no personal settings, clipboard history, development marker, Tesseract installation or language models.
+Download **KSwitcher-win-x64.zip** with **SHA256SUMS.txt**. Keep all three executables together; history uses another instance of KSwitcher.exe. The package contains no personal settings, credentials or clipboard history.

-Build and package:
-
-```powershell
-.\build.ps1 -Stage -Test
-.\package.ps1 -PublishRelease
-```
-
-Commit the archive, checksum and sources together. Publish both assets on a stable `release-vX.Y.Z` tag matching the executable version. Keep `v0.4.2` as the last legacy tag.
+Publish stable `release-vX.Y.Z` tags matching the executable version. Keep `v0.4.2` as the last legacy tag.
@@ -1 +1 @@
-0b3c4fd1346d0b4eeb73d276193c5d2789fd32986c3cc75384cf489f23629678  KSwitcher-win-x64.zip
+008f34a2a4a875acb07d21a39c0fad3a0cb63371edbcb91d393edf72543aea5e  KSwitcher-win-x64.zip
@@ -15,8 +15,8 @@ Set-Content -LiteralPath (Join-Path (Split-Path $executablePath) '.local-dev') -
 Push-Location $root
 try {
    $common = @('-std=c++20','-Os','-DNDEBUG','-DUNICODE','-D_UNICODE','-DWIN32_LEAN_AND_MEAN','-DNOMINMAX','-D_WIN32_WINNT=0x0A00','-Wall','-Wextra','-Wno-missing-field-initializers','-Isrc','-Ivendor','-ffunction-sections','-fdata-sections')
-    $libs = @('-luser32','-lshell32','-lshlwapi','-ladvapi32','-lcrypt32','-limm32','-lcomctl32','-lgdi32','-lole32','-loleaut32','-ltaskschd','-lcomdlg32','-luuid','-lwindowscodecs','-lruntimeobject','-luiautomationcore')
-    foreach ($name in @('core','platform','autostart','autocorrect','storage','ocr','richtext','update','screenshot','screenshot_main','screenshot_notifications','screenshot_activation','screenshot_launcher','app','ui','main','configuration','config_main')) {
+    $libs = @('-lwinhttp','-luser32','-lshell32','-lshlwapi','-ladvapi32','-lcrypt32','-limm32','-lcomctl32','-lgdi32','-lole32','-loleaut32','-ltaskschd','-lcomdlg32','-luuid','-lwindowscodecs','-lruntimeobject','-luiautomationcore')
+    foreach ($name in @('core','platform','autostart','autocorrect','storage','sync','ocr','richtext','update','screenshot','screenshot_main','screenshot_notifications','screenshot_activation','screenshot_launcher','app','ui','main','configuration','config_main')) {
        & $compiler @common -c "src/$name.cpp" -o "build/$name.o"
        if ($LASTEXITCODE) { throw "Compilation failed: $name" }
    }
@@ -29,27 +29,35 @@ try {
    & windres --codepage=65001 -DKS_SCREENSHOT_RESOURCES resources/app.rc -O coff -o build/screenshot-res.o
    if ($LASTEXITCODE) { throw 'Screenshot resource compilation failed' }
    New-Item -ItemType Directory -Force build/release | Out-Null
-    & $compiler -mwindows -municode -static -s '-Wl,--gc-sections' build/core.o build/platform.o build/autostart.o build/autocorrect.o build/storage.o build/ocr.o build/richtext.o build/update.o build/screenshot_launcher.o build/screenshot_activation.o build/screenshot_notifications.o build/app.o build/configuration.o build/ui-resident.o build/main.o build/app-res.o @libs -o $executablePath
+    & $compiler -mwindows -municode -static -s '-Wl,--gc-sections' build/core.o build/platform.o build/autostart.o build/autocorrect.o build/storage.o build/sync.o build/ocr.o build/richtext.o build/update.o build/screenshot_launcher.o build/screenshot_activation.o build/screenshot_notifications.o build/app.o build/configuration.o build/ui-resident.o build/main.o build/app-res.o @libs -o $executablePath
    if ($LASTEXITCODE) { throw 'Link failed' }
    Copy-Item -LiteralPath $executablePath -Destination build/release/KSwitcher.exe -Force
    $configPath = Join-Path (Split-Path $executablePath) 'KSwitcher.Config.exe'
-    & $compiler -mwindows -municode -static -s '-Wl,--gc-sections' build/core.o build/platform.o build/storage.o build/ocr.o build/configuration.o build/config_main.o build/ui-config.o build/app-res.o @libs -o $configPath
+    & $compiler -mwindows -municode -static -s '-Wl,--gc-sections' build/core.o build/platform.o build/storage.o build/sync.o build/ocr.o build/configuration.o build/config_main.o build/ui-config.o build/app-res.o @libs -o $configPath
    if ($LASTEXITCODE) { throw 'Configurator link failed' }
    Copy-Item -LiteralPath $configPath -Destination build/release/KSwitcher.Config.exe -Force
    $screenshotPath = Join-Path (Split-Path $executablePath) 'KSwitcher.Screenshot.exe'
-    & $compiler -mwindows -municode -static -s '-Wl,--gc-sections' build/core.o build/platform.o build/ocr.o build/screenshot.o build/screenshot_notifications.o build/screenshot_activation.o build/screenshot_main.o build/screenshot-res.o @libs -o $screenshotPath
+    & $compiler -mwindows -municode -static -s '-Wl,--gc-sections' build/core.o build/platform.o build/storage.o build/ocr.o build/screenshot.o build/screenshot_notifications.o build/screenshot_activation.o build/screenshot_main.o build/screenshot-res.o @libs -o $screenshotPath
    if ($LASTEXITCODE) { throw 'Screenshot link failed' }
    Copy-Item -LiteralPath $screenshotPath -Destination build/release/KSwitcher.Screenshot.exe -Force
    if ($Test) {
+        & $compiler @common tests/dictionary.cpp build/core.o build/platform.o build/autocorrect.o @libs -lpsapi -static -s -o build/KSwitcherDictionaryTests.exe
+        if ($LASTEXITCODE) { throw 'Dictionary test build failed' }
+        & .\build\KSwitcherDictionaryTests.exe
+        if ($LASTEXITCODE) { throw 'Dictionary tests failed' }
+        & $compiler @common tests/sync.cpp build/core.o build/platform.o build/storage.o build/sync.o build/ocr.o @libs -static -s -o build/KSwitcherSyncTests.exe
+        if ($LASTEXITCODE) { throw 'Sync test build failed' }
+        & .\build\KSwitcherSyncTests.exe
+        if ($LASTEXITCODE) { throw 'Sync tests failed' }
        & $compiler @common tests/scroll.cpp @libs -static -s -o build/KSwitcherScrollTests.exe
        if ($LASTEXITCODE) { throw 'Scroll test build failed' }
        & .\build\KSwitcherScrollTests.exe
        if ($LASTEXITCODE) { throw 'Scroll tests failed' }
-        & $compiler @common tests/tests.cpp build/core.o build/platform.o build/autostart.o build/autocorrect.o build/storage.o build/ocr.o build/richtext.o build/update.o @libs -static -s -o build/KSwitcherTests.exe
+        & $compiler @common tests/tests.cpp build/core.o build/platform.o build/autostart.o build/autocorrect.o build/storage.o build/sync.o build/ocr.o build/richtext.o build/update.o @libs -static -s -o build/KSwitcherTests.exe
        if ($LASTEXITCODE) { throw 'Test build failed' }
        & .\build\KSwitcherTests.exe
        if ($LASTEXITCODE) { throw 'Tests failed' }
-        & $compiler @common tests/input.cpp build/core.o build/platform.o build/autostart.o build/autocorrect.o build/storage.o build/ocr.o build/richtext.o build/update.o build/screenshot.o build/screenshot_launcher.o build/screenshot_activation.o build/screenshot_notifications.o build/app.o build/configuration.o build/ui.o build/screenshot-res.o @libs -static -s -o build/KSwitcherInputTests.exe
+        & $compiler @common tests/input.cpp build/core.o build/platform.o build/autostart.o build/autocorrect.o build/storage.o build/sync.o build/ocr.o build/richtext.o build/update.o build/screenshot.o build/screenshot_launcher.o build/screenshot_activation.o build/screenshot_notifications.o build/app.o build/configuration.o build/ui.o build/screenshot-res.o @libs -static -s -o build/KSwitcherInputTests.exe
        if ($LASTEXITCODE) { throw 'Input test build failed' }
        & .\build\KSwitcherInputTests.exe
        if ($LASTEXITCODE) { throw 'Input tests failed' }
@@ -57,6 +65,8 @@ try {
        if ($LASTEXITCODE) { throw 'Screenshot UI test build failed' }
        & .\build\KSwitcherScreenshotUITests.exe
        if ($LASTEXITCODE) { throw 'Screenshot UI tests failed' }
+        & .\build\KSwitcherScreenshotUITests.exe --save-only
+        if ($LASTEXITCODE) { throw 'Screenshot save tests failed' }
        $registrationTest = Join-Path (Split-Path $executablePath) 'KSwitcherRegistrationTests.exe'
        try {
            & $compiler @common tests/screenshot_registration.cpp build/core.o build/platform.o @libs -static '-Wl,--gc-sections' -s -o $registrationTest
@@ -71,15 +81,35 @@ try {
        if ($LASTEXITCODE) { throw 'Updater progress UI tests failed' }
    }
    if ($Integration) {
-        & $compiler @common tests/integration.cpp build/core.o build/platform.o build/autostart.o build/autocorrect.o build/storage.o build/ocr.o build/richtext.o build/update.o build/screenshot.o build/screenshot_launcher.o build/screenshot_activation.o build/screenshot_notifications.o build/app.o build/configuration.o build/ui.o build/screenshot-res.o @libs -static -s -o build/KSwitcherIntegration.exe
+        $historyFixture = Join-Path (Resolve-Path build) ('history-host-fixture-' + [guid]::NewGuid().ToString('N'))
+        New-Item -ItemType Directory $historyFixture | Out-Null
+        Copy-Item $executablePath,(Join-Path (Split-Path $executablePath) 'KSwitcher.Screenshot.exe') -Destination $historyFixture
+        Set-Content (Join-Path $historyFixture '.local-dev') 'Isolated history integration test'
+        $historyTest = Join-Path $historyFixture 'KSwitcherHistoryHostTests.exe'
+        & $compiler @common tests/history_host.cpp build/core.o build/platform.o build/storage.o build/ocr.o @libs -lpsapi -static -s -o $historyTest
+        if ($LASTEXITCODE) { throw 'History host test build failed' }
+        & $historyTest
+        if ($LASTEXITCODE) { throw 'History host tests failed' }
+        $snapshotTest = Join-Path (Split-Path $executablePath) 'KSwitcherClipboardSnapshotTests.exe'
+        & $compiler @common tests/clipboard_snapshot.cpp build/core.o build/platform.o build/storage.o build/ocr.o @libs -lpsapi -static -s -o $snapshotTest
+        if ($LASTEXITCODE) { throw 'Clipboard snapshot test build failed' }
+        & $snapshotTest
+        if ($LASTEXITCODE) { throw 'Clipboard snapshot tests failed' }
+        $captureTest = Join-Path (Split-Path $executablePath) 'KSwitcherImageCaptureTests.exe'
+        & $compiler @common tests/image_capture.cpp build/core.o build/platform.o build/storage.o build/ocr.o @libs -static -s -o $captureTest
+        if ($LASTEXITCODE) { throw 'Image capture test build failed' }
+        & $captureTest
+        if ($LASTEXITCODE) { throw 'Image capture tests failed' }
+        & $compiler @common tests/integration.cpp build/core.o build/platform.o build/autostart.o build/autocorrect.o build/storage.o build/sync.o build/ocr.o build/richtext.o build/update.o build/screenshot.o build/screenshot_launcher.o build/screenshot_activation.o build/screenshot_notifications.o build/app.o build/configuration.o build/ui.o build/screenshot-res.o @libs -static -s -o build/KSwitcherIntegration.exe
        if ($LASTEXITCODE) { throw 'Integration test build failed' }
        & .\build\KSwitcherIntegration.exe
        if ($LASTEXITCODE) { throw 'Integration tests failed' }
    }
    if ($Ocr) {
-        & $compiler @common tests/ocr.cpp build/core.o build/platform.o build/autostart.o build/autocorrect.o build/storage.o build/ocr.o build/richtext.o build/update.o build/screenshot.o build/screenshot_launcher.o build/screenshot_activation.o build/screenshot_notifications.o build/app.o build/configuration.o build/ui.o build/screenshot-res.o @libs -static -s -o build/KSwitcherOcrTests.exe
+        $ocrTest = Join-Path (Split-Path $executablePath) 'KSwitcherOcrTests.exe'
+        & $compiler @common tests/ocr.cpp build/core.o build/platform.o build/autostart.o build/autocorrect.o build/storage.o build/sync.o build/ocr.o build/richtext.o build/update.o build/screenshot.o build/screenshot_launcher.o build/screenshot_activation.o build/screenshot_notifications.o build/app.o build/configuration.o build/ui.o build/screenshot-res.o @libs -static -s -o $ocrTest
        if ($LASTEXITCODE) { throw 'OCR test build failed' }
-        & .\build\KSwitcherOcrTests.exe
+        & $ocrTest
        if ($LASTEXITCODE) { throw 'OCR tests failed' }
    }
    foreach ($folder in @('build/dictionaries','build/release/dictionaries','build/staged/dictionaries')) {
@@ -17,7 +17,7 @@ replace counts with original frequency ranks, sort lexically. Reproduce with
 hashes. The lists contain word forms from subtitles, not a complete spelling
 or grammar dictionary. Recognition can miss names, jargon and uncommon forms.

-Supplemental Ukrainian vocabulary: `реліз`. These additions use rank 50001,
+Supplemental Ukrainian vocabulary: `реліз`, `поточні`. These additions use rank 50001,
 after the upstream 50k list, rather than claiming a measured corpus frequency.
 They are included with the default unlimited rank setting and recorded in sources.json.

@@ -9,11 +9,12 @@
  "uk": {
    "source": "https://raw.githubusercontent.com/hermitdave/FrequencyWords/525f9b560de45753a5ea01069454e72e9aa541c6/content/2016/uk/uk_50k.txt",
    "sourceSha256": "9548b79a608d33f39c5546037a69117d679730b1fda08dd0ce67c043dbf3335a",
-    "words": 42550,
-    "bytes": 898227,
-    "sha256": "c94605e6be676d2d64f89a3bc16f92b9128f9977d226a97b103cf22a3e6835e3",
+    "words": 42551,
+    "bytes": 898248,
+    "sha256": "caeb097749d4afc84b68ad96b3d7dfb6a6569561cd32ccce0bee94a13b43ba86",
    "supplementalWords": {
-      "\u0440\u0435\u043b\u0456\u0437": 50001
+      "\u0440\u0435\u043b\u0456\u0437": 50001,
+      "\u043f\u043e\u0442\u043e\u0447\u043d\u0456": 50001
    }
  },
  "ru": {
@@ -27337,6 +27337,7 @@
 поторопись	9062
 поторопитесь	20656
 поторопиться	15390
+поточні	50001
 потрапив	4168
 потрапила	7383
 потрапили	6631
@@ -9,8 +9,8 @@ IDC_SCREENSHOT_PENCIL CURSOR "icons/lucide/pencil.cur"
 1 RT_MANIFEST "app.manifest"
 201 RCDATA "update.ps1"
 1 VERSIONINFO
- FILEVERSION 0,6,20,0
- PRODUCTVERSION 0,6,20,0
+ FILEVERSION 0,6,43,0
+ PRODUCTVERSION 0,6,43,0
 FILEOS VOS_NT_WINDOWS32
 FILETYPE VFT_APP
 BEGIN
@@ -20,7 +20,7 @@ BEGIN
  BEGIN
   VALUE "FileDescription", "KSwitcher — native keyboard and clipboard utility"
   VALUE "ProductName", "KSwitcher"
-   VALUE "FileVersion", "0.6.20"
+   VALUE "FileVersion", "0.6.43"
  END
 END
 BLOCK "VarFileInfo"
@@ -1,4 +1,6 @@
 #include "app.h"
+#include <utility>
+#include "../vendor/json.hpp"
 #include "../resources/resource.h"
 #include "ocr.h"
 #include "configuration.h"
@@ -11,7 +13,9 @@

 namespace ks
 {
+#include "app_sync.inl"
 App *App::current = nullptr;
+#include "app_history.inl"
 namespace
 {
 const char *transformCommandName(int command)
@@ -68,21 +72,43 @@ class Transaction
    App &app;
    HWND target;
    uint64_t version;
-    Clip snapshot;
+    ClipboardSnapshot snapshot;
    DWORD expected{};
    bool captured{};
+    mutable bool invalidLogged{};
+    unsigned copyNumber{};
    std::wstring adopted;
+    Bytes adoptedFormats;
+    bool trustedContentsObserved{};
+    std::unique_ptr<PasteProbe> selectionProof;
+    std::wstring provenSelection;

  public:
    Transaction(App &a, HWND t, uint64_t v) : app(a), target(t), version(v)
    {
        app.suspended = true;
        try
+        {
+            for (unsigned attempt = 0; ; ++attempt)
            {
                expected = GetClipboardSequenceNumber();
-            snapshot = readClipboard(app.window, 64 * 1024 * 1024);
+                try
+                {
+                    snapshot.capture(app.window, expected);
                    if (expected != GetClipboardSequenceNumber())
                        throw std::runtime_error("Clipboard changed while taking snapshot");
+                    break;
+                }
+                catch (...)
+                {
+                    // No selection or clipboard write has happened yet. Recapture
+                    // the latest clipboard after a concurrent publisher settles.
+                    if (attempt >= 2 || !valid() || expected == GetClipboardSequenceNumber())
+                        throw;
+                    diagnosticEvent(L"Snapshot retry: clipboard changed during capture");
+                    Sleep(20);
+                }
+            }
            captured = true;
        }
        catch (...)
@@ -96,7 +122,7 @@ class Transaction
        if (captured && GetClipboardSequenceNumber() == expected)
            try
            {
-                app.ownSequence = writeClipboard(app.window, snapshot);
+                app.ownSequence = snapshot.restore(app.window, expected);
            }
            catch (...)
            {
@@ -106,17 +132,37 @@ class Transaction
    }
    bool valid() const
    {
-        return target && IsWindow(target) && GetForegroundWindow() == target &&
-               app.inputVersion.load() == version;
+        auto foreground = GetForegroundWindow();
+        auto currentVersion = app.inputVersion.load();
+        bool ok = target && IsWindow(target) && foreground == target && currentVersion == version;
+        if (!ok && !invalidLogged)
+        {
+            invalidLogged = true;
+            diagnosticEvent(L"Context invalid: target=" + std::to_wstring((uintptr_t)target) +
+                L" alive=" + std::to_wstring(IsWindow(target)) + L" foreground=" +
+                std::to_wstring((uintptr_t)foreground) + L" expectedVersion=" + std::to_wstring(version) +
+                L" currentVersion=" + std::to_wstring(currentVersion));
+        }
+        return ok;
    }
    void check()
    {
        if (GetClipboardSequenceNumber() != expected)
        {
            auto now = GetClipboardSequenceNumber();
-            if (adopted.empty() || !ownsClipboard(target) || readClipboard(app.window).text() != adopted ||
-                GetClipboardSequenceNumber() != now)
+            auto current = readClipboard(app.window, 32 * 1024 * 1024, ClipboardRead::Selection);
+            const bool sameContents = selectionClipboardIdentity(current) == adoptedFormats;
+            if (adopted.empty() || (!trustedContentsObserved && !ownsClipboard(target)) ||
+                !sameContents || GetClipboardSequenceNumber() != now)
+            {
+                diagnosticEvent(L"Clipboard check rejected: expectedSequence=" + std::to_wstring(expected) +
+                    L" readSequence=" + std::to_wstring(now) + L" currentSequence=" +
+                    std::to_wstring(GetClipboardSequenceNumber()) + L" owner=" +
+                    std::to_wstring((uintptr_t)GetClipboardOwner()) + L" sameContents=" +
+                    std::to_wstring(sameContents) + L" expectedText=" + diagnosticText(adopted) +
+                    L" currentText=" + diagnosticText(current.text()));
                throw std::runtime_error("Operation cancelled: another application changed the clipboard");
+            }
            expected = now;
        }
    }
@@ -124,6 +170,8 @@ class Transaction
    {
        check();
        adopted.clear();
+        adoptedFormats.clear();
+        trustedContentsObserved = false;
        // These are temporary transaction contents, not a user's clipboard entry.
        // In particular, do not invite the Windows history service to read our
        // sentinel while the target editor is trying to open the clipboard.
@@ -136,16 +184,22 @@ class Transaction
        if (GetClipboardOwner() != app.window)
            throw std::runtime_error("Clipboard changed immediately after writing");
        auto text = c.text();
-        if ((!text.empty() && readClipboard(app.window).text() != text) ||
+        if ((!text.empty() && readClipboard(app.window, 32 * 1024 * 1024, ClipboardRead::Selection).text() != text) ||
            GetClipboardSequenceNumber() != expected)
            throw std::runtime_error("Clipboard changed while verifying our write");
    }
    std::wstring copy()
    {
+        const auto started = GetTickCount64();
+        const auto number = ++copyNumber;
        if (!valid())
            return {};
-        write(textClip(L"\x2063KSwitcher-" + std::to_wstring(GetTickCount64())));
+        const auto sentinel = L"\x2063KSwitcher-" + std::to_wstring(GetTickCount64());
+        write(textClip(sentinel));
        DWORD before = expected;
+        diagnosticEvent(L"Copy begin number=" + std::to_wstring(number) + L" sentinelSequence=" +
+            std::to_wstring(before) + L" target=" + std::to_wstring((uintptr_t)target) +
+            L" sentinel=" + diagnosticText(sentinel));
        if (!valid() || !chord(L'C', MOD_CONTROL))
        {
            diagnosticEvent(L"Copy failed: context changed or simulated Ctrl+C blocked");
@@ -157,6 +211,7 @@ class Transaction
        DWORD changed = before;
        ULONGLONG stable = 0;
        bool changedAgain = false;
+        std::optional<Bytes> observedTargetCopy;
        while (GetTickCount64() < deadline)
        {
            if (!valid())
@@ -164,9 +219,25 @@ class Transaction
            DWORD now = GetClipboardSequenceNumber();
            if (now != changed)
            {
+                diagnosticEvent(L"Copy sequence number=" + std::to_wstring(number) + L" from=" +
+                    std::to_wstring(changed) + L" to=" + std::to_wstring(now) + L" elapsedMs=" +
+                    std::to_wstring(GetTickCount64() - started) + L" owner=" +
+                    std::to_wstring((uintptr_t)GetClipboardOwner()));
                changedAgain |= changed != before;
                changed = now;
                stable = GetTickCount64();
+                // Clipboard synchronizers can republish a legitimate copy under
+                // their own HWND. Record provenance before that handoff; an
+                // unobserved or altered foreign copy must still be rejected.
+                if (ownsClipboard(target))
+                {
+                    auto candidate = readClipboard(app.window, 32 * 1024 * 1024, ClipboardRead::Selection);
+                    if (GetClipboardSequenceNumber() == now && ownsClipboard(target) && !candidate.text().empty())
+                    {
+                        observedTargetCopy = selectionClipboardIdentity(candidate);
+                        diagnosticEvent(L"Copy: target-owned selection observed number=" + std::to_wstring(number));
+                    }
+                }
            }
            if (changed != before && GetTickCount64() - stable >= 60)
                break;
@@ -181,7 +252,8 @@ class Transaction
                    return {};
                if (!chord(L'C', MOD_CONTROL))
                    return {};
-                diagnosticEvent(L"Copy retry: clipboard unchanged after Ctrl+C");
+                diagnosticEvent(L"Copy retry: clipboard unchanged after Ctrl+C number=" + std::to_wstring(number) +
+                    L" attempt=" + std::to_wstring(attempts + 1) + L" elapsedMs=" + std::to_wstring(GetTickCount64() - started));
                ++attempts;
                retryAt = GetTickCount64() + 250;
            }
@@ -189,17 +261,39 @@ class Transaction
        }
        if (changed == before || !valid())
        {
+            diagnosticEvent(L"Copy end number=" + std::to_wstring(number) + L" attempts=" +
+                std::to_wstring(attempts) + L" elapsedMs=" + std::to_wstring(GetTickCount64() - started) +
+                L" sequence=" + std::to_wstring(GetClipboardSequenceNumber()) + L" clipboardOpenBy=" +
+                std::to_wstring((uintptr_t)GetOpenClipboardWindow()));
            diagnosticEvent(changed == before ? L"Copy failed: clipboard timeout (2000 ms)" :
                                    L"Copy failed: context changed");
            return {};
        }
-        if ((GetClipboardOwner() ? !ownsClipboard(target) : changedAgain) ||
+        const bool targetOwned = ownsClipboard(target);
+        auto clip = readClipboard(app.window, 32 * 1024 * 1024, ClipboardRead::Selection);
+        const auto formats = selectionClipboardIdentity(clip);
+        const bool verifiedRelay = observedTargetCopy && *observedTargetCopy == formats;
+        if (((GetClipboardOwner() ? !targetOwned : changedAgain) && !verifiedRelay) ||
            changed != GetClipboardSequenceNumber())
+        {
+            diagnosticEvent(L"Copy rejected: observedTarget=" + std::to_wstring(observedTargetCopy.has_value()) +
+                L" verifiedRelay=" + std::to_wstring(verifiedRelay) + L" expectedSequence=" +
+                std::to_wstring(changed) + L" currentSequence=" + std::to_wstring(GetClipboardSequenceNumber()) +
+                L" owner=" + std::to_wstring((uintptr_t)GetClipboardOwner()) + L" targetText=" +
+                diagnosticText(observedTargetCopy ? decodeClip(*observedTargetCopy).text() : L"") +
+                L" currentText=" + diagnosticText(clip.text()));
            throw std::runtime_error("Operation cancelled: copy did not belong to the target application");
+        }
+        if (!targetOwned && verifiedRelay)
+            diagnosticEvent(L"Copy: identical target selection republished by clipboard synchronizer");
        expected = changed;
-        auto clip = readClipboard(app.window);
        auto text = clip.text();
+        diagnosticEvent(L"Copy result number=" + std::to_wstring(number) + L" attempts=" +
+            std::to_wstring(attempts) + L" elapsedMs=" + std::to_wstring(GetTickCount64() - started) +
+            L" text=" + diagnosticText(text));
        adopted = text;
+        adoptedFormats = formats;
+        trustedContentsObserved = targetOwned || verifiedRelay;
        check();
        for (auto &f : clip.formats)
        {
@@ -220,16 +314,57 @@ class Transaction
                }
            }
        }
+        selectionProof.reset();
+        provenSelection.clear();
+        // Viber and some other editors omit trailing ASCII spaces from Ctrl+C.
+        // Recover only from a real selection, never from the recorded keys alone.
+        if (valid() && !text.empty() && text.size() < 8192 && text.back() != L' ')
+        {
+            auto proof = std::make_unique<PasteProbe>(true, target);
+            auto selected = proof->read(1, false);
+            if (selected && selected->size() > text.size() && selected->starts_with(text) &&
+                selected->find_first_not_of(L' ', text.size()) == std::wstring::npos && valid())
+            {
+                diagnosticEvent(L"Copy: trailing spaces verified via accessibility copied=" +
+                    diagnosticText(text) + L" selected=" + diagnosticText(*selected));
+                text = *selected;
+                provenSelection = text;
+                selectionProof = std::move(proof);
+            }
+        }
        return text;
    }
+    bool recoveredSelection() const { return selectionProof != nullptr; }
    bool select(size_t n)
    {
        return selectPrevious(n, [&] { return valid(); });
    }
    std::wstring copyRange(size_t count, const std::wstring &wordCandidate,
-                           const std::function<bool(const std::wstring &)> &matches)
+                           const std::function<bool(const std::wstring &)> &matches,
+                           const std::function<bool(const std::wstring &)> &suffixMatches = {})
    {
        // WebView word boundaries are only candidates; exact verification is mandatory.
+        diagnosticEvent(L"Selection begin steps=" + std::to_wstring(count) + L" expected=" + diagnosticText(wordCandidate));
+        GUITHREADINFO gui{sizeof(gui)};
+        if (GetGUIThreadInfo(GetWindowThreadProcessId(target, nullptr), &gui))
+        {
+            wchar_t cls[128]{};
+            GetClassNameW(gui.hwndFocus, cls, 128);
+            std::wstring offsets = L"unavailable";
+            if (_wcsicmp(cls, L"Edit") == 0)
+            {
+                DWORD_PTR range{};
+                if (SendMessageTimeoutW(gui.hwndFocus, EM_GETSEL, 0, 0,
+                                       SMTO_ABORTIFHUNG | SMTO_BLOCK, 25, &range) && (DWORD)range != 0xffffffff)
+                    offsets = std::to_wstring(LOWORD(range)) + L"," + std::to_wstring(HIWORD(range));
+            }
+            diagnosticEvent(L"Selection editor class=" + std::wstring(cls) + L" focus=" +
+                std::to_wstring((uintptr_t)gui.hwndFocus) + L" caretWindow=" + std::to_wstring((uintptr_t)gui.hwndCaret) +
+                L" caretRect=" + std::to_wstring(gui.rcCaret.left) + L"," + std::to_wstring(gui.rcCaret.top) +
+                L"," + std::to_wstring(gui.rcCaret.right) + L"," + std::to_wstring(gui.rcCaret.bottom) +
+                L" layout=" + std::to_wstring((uintptr_t)windowLayout(target)) + L" selectionOffsets=" + offsets);
+        }
+        else diagnosticEvent(L"Selection editor: focus/caret/selection unavailable");
        if (needsSelectionDelay(target) && !wordCandidate.empty() &&
            std::all_of(wordCandidate.begin(), wordCandidate.end(),
                        [](wchar_t c) { return letter(c) || iswdigit(c); }))
@@ -238,6 +373,7 @@ class Transaction
                return {};
            Sleep(25);
            auto text = copy();
+            diagnosticEvent(L"Selection word-boundary match=" + std::to_wstring(matches(text)) + L" copied=" + diagnosticText(text));
            if (valid() && matches(text))
            {
                diagnosticEvent(L"Selection: verified word boundary");
@@ -247,13 +383,58 @@ class Transaction
                return {};
            Sleep(25);
        }
-        return select(count) ? copy() : std::wstring{};
+        auto text = select(count) ? copy() : std::wstring{};
+        diagnosticEvent(L"Selection initial match=" + std::to_wstring(matches(text)) + L" copied=" + diagnosticText(text));
+        // Chromium editors can apply only part of a burst of Shift+Left events.
+        // Extend only a verified suffix; never replace a partial or unrelated range.
+        if (valid() && !matches(text) && !text.empty() &&
+            (suffixMatches ? suffixMatches(text) : newlines(wordCandidate).ends_with(newlines(text))) &&
+            caretSteps(text) < count)
+        {
+            const auto missing = count - caretSteps(text);
+            diagnosticEvent(L"Selection: extending verified suffix by " + std::to_wstring(missing));
+            for (size_t i = 0; i < missing; ++i)
+            {
+                if (!valid() || !chord(VK_LEFT, MOD_SHIFT))
+                    return {};
+                diagnosticEvent(L"Selection recovery Shift+Left sent=" + std::to_wstring(i + 1) + L" total=" + std::to_wstring(missing));
+                Sleep(25);
+            }
+            text = copy();
+            diagnosticEvent(L"Selection: suffix recovery match=" + std::to_wstring(matches(text)) + L" copied=" + diagnosticText(text));
+        }
+        return text;
    }
    bool paste(const Clip &clip)
    {
+        if (selectionProof)
+        {
+            auto selected = selectionProof->read(1, false);
+            if (!selected || *selected != provenSelection || !valid())
+            {
+                diagnosticEvent(L"Paste cancelled: recovered selection changed or unavailable");
+                return false;
+            }
+        }
        if (!valid())
            return false;
        write(clip);
+        // Our verified payload is also trusted across an identical relay. The
+        // sentinel written by copy() deliberately does not get this allowance.
+        if (clip.formats.size() == 1 && clip.formats.front().id == CF_UNICODETEXT)
+        {
+            adopted = clip.text();
+            adoptedFormats = selectionClipboardIdentity(clip);
+            trustedContentsObserved = true;
+        }
+        // Viber's Qt editor observes clipboard changes asynchronously. Give it
+        // a chance to discard the data object from Ctrl+C before requesting paste.
+        // Recheck ownership and input below; never retry a possibly applied paste.
+        if (lower(processName(target)) == L"viber")
+        {
+            Sleep(75);
+            diagnosticEvent(L"Paste: Viber clipboard notification settling interval completed");
+        }
        for (int i = 0; i < 2; ++i)
        {
            check();
@@ -263,11 +444,42 @@ class Transaction
        if (!chord(L'V', MOD_CONTROL))
            throw std::runtime_error("Windows blocked simulated input; check application privilege levels");
        Sleep(300);
+        // A clipboard synchronizer may replace our payload after Ctrl+V is
+        // queued but before the editor consumes it. Do not run snippet actions
+        // (especially Enter) after such a race.
+        check();
        return true;
    }
+    bool nativeSelectionIs(const std::wstring &original) const
+    {
+        if (!valid()) return false;
+        GUITHREADINFO gui{sizeof(gui)};
+        if (!GetGUIThreadInfo(GetWindowThreadProcessId(target, nullptr), &gui) || !gui.hwndFocus) return false;
+        wchar_t cls[32]{};
+        GetClassNameW(gui.hwndFocus, cls, 32);
+        if (_wcsicmp(cls, L"Edit") != 0 ||
+            (GetWindowLongPtrW(gui.hwndFocus, GWL_STYLE) & (ES_PASSWORD | ES_READONLY))) return false;
+        auto query = [&](UINT message, WPARAM wp, LPARAM lp, DWORD_PTR &result)
+        {
+            return SendMessageTimeoutW(gui.hwndFocus, message, wp, lp,
+                                       SMTO_ABORTIFHUNG | SMTO_BLOCK, 100, &result) != 0;
+        };
+        DWORD_PTR range{}, length{}, copied{};
+        if (!query(EM_GETSEL, 0, 0, range) || (DWORD)range == 0xffffffff ||
+            size_t(HIWORD(range) - LOWORD(range)) != original.size() ||
+            !query(WM_GETTEXTLENGTH, 0, 0, length) || length > 65534 || HIWORD(range) > length) return false;
+        std::wstring content(length + 1, L'\0');
+        if (!query(WM_GETTEXT, content.size(), (LPARAM)content.data(), copied) || copied != length) return false;
+        DWORD_PTR after{};
+        GUITHREADINFO focused{sizeof(focused)};
+        return query(EM_GETSEL, 0, 0, after) && after == range && valid() &&
+               GetGUIThreadInfo(GetWindowThreadProcessId(target, nullptr), &focused) && focused.hwndFocus == gui.hwndFocus &&
+               content.substr(LOWORD(range), original.size()) == original;
+    }
 };
 } // namespace
-App::App(HINSTANCE h, bool test, const std::filesystem::path &dataRoot) : instance(h), smoke(test)
+App::App(HINSTANCE h, bool test, const std::filesystem::path &dataRoot, HWND service)
+    : historyService(service), instance(h), smoke(test)
 {
    updateNotifier = notifyUpdateAvailable;
    current = this;
@@ -284,7 +496,7 @@ App::App(HINSTANCE h, bool test, const std::filesystem::path &dataRoot) : instan
        registrationWarning = L"Settings were not loaded: " + wide(e.what());
    }
    setLoggingEnabled(settings.writeLog);
-    if (settings.autoCorrect)
+    if (settings.autoCorrect && !historyService)
        try { autoPredictor.configure(std::filesystem::path(executable()).parent_path() / L"dictionaries", settings.autoLanguages); }
        catch (const std::exception &e)
        {
@@ -303,6 +515,10 @@ App::App(HINSTANCE h, bool test, const std::filesystem::path &dataRoot) : instan
 }
 App::~App()
 {
+    if (auto host = historyController(historyProcess)) PostMessageW(host, WM_CLOSE, 0, 0);
+    if (historyProcess) CloseHandle(historyProcess);
+    if (notificationRegistration) CloseHandle(notificationRegistration);
+    if (syncWorker.joinable()) syncWorker.join();
    if (updateWorker.joinable())
        updateWorker.join();
    if (keyboardHook)
@@ -396,7 +612,10 @@ void App::scheduleHistoryOcr(const Settings &config)
                        if (!entry.image || (entry.ocrState != 1 && entry.ocrProfile == profile)) continue;
                        try
                        {
-                            auto text = recognizeText(history->load(entry.id), config);
+                            auto text = history->recognizeImage(entry.id, config, [this, &profile] {
+                                std::lock_guard lock(jobsMutex);
+                                return stop || ocrProfile(historyOcrSettings) != profile;
+                            });
                            std::lock_guard lock(jobsMutex);
                            if (stop || ocrProfile(historyOcrSettings) != profile) continue;
                            if (history->saveOcr(entry.id, text, config))
@@ -457,8 +676,16 @@ bool App::registerHotkeys(const Settings &s, bool rollback)
    return true;
 }

-void App::applySettings(const Settings &s)
+void App::applySettings(const Settings &requested)
 {
+    Settings s = requested;
+    std::set<std::wstring> present, removed(s.snippetTombstones.begin(), s.snippetTombstones.end());
+    removed.insert(settings.snippetTombstones.begin(), settings.snippetTombstones.end());
+    for (auto &snippet : s.snippets) { snippet.id = snippetId(snippet); present.insert(snippet.id); }
+    for (const auto &snippet : settings.snippets)
+        if (!present.contains(snippetId(snippet))) removed.insert(snippetId(snippet));
+    for (const auto &id : present) removed.erase(id);
+    s.snippetTombstones.assign(removed.begin(), removed.end());
    bool autostartChanged = false;
    AutoCorrector predictor;
    validateSettings(s);
@@ -502,10 +729,12 @@ void App::applySettings(const Settings &s)
        run.reset();
        last.reset();
        ++inputVersion;
+        if (busy) diagnosticEvent(L"Input context changed: settings applied version=" + std::to_wstring(inputVersion.load()));
    }
-    // Clear on the worker so the next check reloads edits to dictionary files.
+    // Release the worker's old snapshot; the next check shares the freshly loaded predictor.
    enqueue([this] { autoCorrector.configure({}, {}); });
    scheduleHistoryOcr(s);
+    nextSync = std::max(GetTickCount64() + 2000, syncRetryAfter);
    SetThreadExecutionState(ES_CONTINUOUS |
                            (settings.awake ? (ES_DISPLAY_REQUIRED | ES_SYSTEM_REQUIRED) : 0));
 }
@@ -529,11 +758,13 @@ void App::reloadLayouts()
        run.reset();
        last.reset();
        ++inputVersion;
+        if (busy) diagnosticEvent(L"Input context changed: layouts reloaded version=" + std::to_wstring(inputVersion.load()));
    }
    registerHotkeys(settings);
 }
 void App::clearHistory()
 {
+    if (historyService) { remoteHistory("clear"); history->reload(); return; }
    if (busy) throw std::runtime_error("Wait for the current operation to finish.");
    if (history) history->clear();
    if (historyWindow) refreshHistory(*this);
@@ -558,9 +789,17 @@ void App::resetInput()
 {
    std::lock_guard lock(stateMutex);
    ++inputVersion;
+    if (busy) diagnosticEvent(L"Input context changed: reset version=" + std::to_wstring(inputVersion.load()));
    run.reset();
    last.reset();
 }
+void App::releaseIdleMemory(ULONGLONG now)
+{
+    expireDiagnostics(now);
+    std::lock_guard lock(stateMutex);
+    // Match the Undo eligibility deadline; never discard an available operation.
+    if (!busy && last && now - last->at > 120000) last.reset();
+}
 void App::clearLog(bool previous) { clearDiagnosticLog(previous); }
 void App::keyboard(const KBDLLHOOKSTRUCT &k, UINT mods)
 {
@@ -575,6 +814,9 @@ void App::keyboard(const KBDLLHOOKSTRUCT &k, UINT mods)
    if (isHotkey(vk, mods))
        return;
    ++inputVersion;
+    if (busy) diagnosticEvent(L"Input context changed: keyboard vk=" + std::to_wstring(vk) +
+        L" modifiers=" + std::to_wstring(mods) + L" injected=" + std::to_wstring((k.flags & LLKHF_INJECTED) != 0) +
+        L" version=" + std::to_wstring(inputVersion.load()));
    last.reset();
    HWND fg = GetForegroundWindow();
    HKL layout = windowLayout(fg);
@@ -785,6 +1027,15 @@ void App::replayTyping()
 }
 LRESULT CALLBACK App::keyProc(int code, WPARAM wp, LPARAM lp)
 {
+    // MWB suppresses source-machine events that it forwards elsewhere. Let
+    // downstream hooks route the event before tracking it or starting a snippet.
+    // Call the chain exactly once; a local event can still be consumed below.
+    const auto routed = CallNextHookEx(nullptr, code, wp, lp);
+    return keyboardAfterHooks(code, wp, lp, routed);
+}
+LRESULT App::keyboardAfterHooks(int code, WPARAM wp, LPARAM lp, LRESULT routed)
+{
+    if (routed) return routed;
    if (code == HC_ACTION && current &&
        (wp == WM_KEYDOWN || wp == WM_SYSKEYDOWN || wp == WM_KEYUP || wp == WM_SYSKEYUP))
    {
@@ -799,7 +1050,7 @@ LRESULT CALLBACK App::keyProc(int code, WPARAM wp, LPARAM lp)
                                    wp == WM_KEYDOWN || wp == WM_SYSKEYDOWN, mods))
            return 1;
    }
-    return CallNextHookEx(nullptr, code, wp, lp);
+    return routed;
 }
 LRESULT CALLBACK App::mouseProc(int code, WPARAM wp, LPARAM lp)
 {
@@ -808,8 +1059,11 @@ LRESULT CALLBACK App::mouseProc(int code, WPARAM wp, LPARAM lp)
        // KSwitcher generates no mouse input. Remote clicks invalidate a typing
        // range just like local clicks, including while a transaction is pending.
        if (wp == WM_LBUTTONDOWN || wp == WM_RBUTTONDOWN || wp == WM_MBUTTONDOWN || wp == WM_MOUSEWHEEL)
+        {
+            if (current->busy) diagnosticEvent(L"Input context changed: mouse message=" + std::to_wstring(wp));
            current->resetInput();
        }
+    }
    return CallNextHookEx(nullptr, code, wp, lp);
 }
 void App::dispatch(int command)
@@ -979,9 +1233,10 @@ void App::transform(int command, int snippet)
                                    !(command == 0 && reason == L"paste-sent-unverified")},
                                {"elapsedMs", GetTickCount64() - start}, {"foregroundSame", GetForegroundWindow() == target},
                                {"inputSame", app.inputVersion.load() == version}, {"original", bounded(text)},
-                                {"expected", bounded(result)}, {"actual", bounded(actual)},
-                                {"originalUnits", text.size()}, {"expectedUnits", result.size()}, {"actualUnits", actual.size()},
-                                {"textTruncated", text.size() > 4096 || result.size() > 4096 || actual.size() > 4096}};
+                                {"expected", bounded(verification == L"selection-mismatch" ? expected : result)}, {"actual", bounded(actual)},
+                                {"selectionExpected", bounded(expected)},
+                                {"originalUnits", text.size()}, {"expectedUnits", (verification == L"selection-mismatch" ? expected : result).size()}, {"actualUnits", actual.size()},
+                                {"textTruncated", text.size() > 4096 || result.size() > 4096 || actual.size() > 4096 || expected.size() > 4096}};
                            diagnosticOperation(record.dump(-1, ' ', true, DiagnosticJson::error_handler_t::replace));
                        }
                        catch (...) {} // Logging must never abort a completed input transaction.
@@ -1017,9 +1272,11 @@ void App::transform(int command, int snippet)
                    if (!config.autoCorrect || recent.window != target || recent.overflow ||
                        recent.keys.empty() || recent.keys.back() != L' ' || hint < 0)
                        return;
-                    autoCorrector.configure(std::filesystem::path(executable()).parent_path() /
-                                                L"dictionaries",
-                                            config.autoLanguages);
+                    {
+                        std::lock_guard lock(stateMutex);
+                        if (inputVersion.load() != version) return;
+                        autoCorrector.shareDictionaries(autoPredictor);
+                    }
                    std::wstring predicted;
                    for (wchar_t key : recent.keys)
                        predicted += key == L' ' ? L' ' : available[hint].at(physicalLayout().code(key));
@@ -1104,6 +1361,8 @@ void App::transform(int command, int snippet)
                    if (newlines(text) != newlines(previous->result))
                    {
                        reason = L"undo-verification-mismatch";
+                        actual = text;
+                        verification = L"selection-mismatch";
                        if (tx.valid())
                            chord(VK_RIGHT);
                        return;
@@ -1138,12 +1397,16 @@ void App::transform(int command, int snippet)
                {
                    text =
                        tx.copyRange(recent.keys.size(), recent.keys, [&](const std::wstring &candidate)
-                                     { return recent.match(candidate, available, physicalLayout()) >= 0; });
+                                     { return recent.match(candidate, available, physicalLayout()) >= 0; },
+                                     [&](const std::wstring &candidate)
+                                     { return recent.matchSuffix(candidate, available, physicalLayout()) >= 0; });
                    hint = recent.match(text, available, physicalLayout());
                    diagnosticEvent(L"Recent verification copied=" + std::to_wstring(text.size()) + L" keys=" +
                        std::to_wstring(recent.keys.size()) + L" match=" + std::to_wstring(hint));
                    if (hint < 0)
                    {
+                        actual = text;
+                        verification = L"selection-mismatch";
                        reason = text.empty() ? L"recent-copy-empty" : L"recent-verification-mismatch";
                        if (tx.valid())
                            chord(VK_RIGHT);
@@ -1155,12 +1418,20 @@ void App::transform(int command, int snippet)
                         previous->version == version)
                {
                    expected = previous->result;
+                    diagnosticEvent(L"Previous result expected=" + diagnosticText(expected));
                    text = tx.copyRange(caretSteps(previous->result), previous->result,
                                        [&](const std::wstring &candidate)
                                        { return newlines(candidate) == newlines(previous->result); });
                    if (newlines(text) != newlines(previous->result))
                    {
+                        actual = text;
+                        verification = L"selection-mismatch";
                        reason = L"previous-result-verification-mismatch";
+                        {
+                            std::lock_guard lock(stateMutex);
+                            last.reset();
+                            run.reset();
+                        }
                        if (tx.valid())
                            chord(VK_RIGHT);
                        return;
@@ -1202,23 +1473,36 @@ void App::transform(int command, int snippet)
                                    chord(VK_RIGHT);
                                return;
                            }
-                            int source = detect(text, available, hint);
-                            if (source < 0)
-                                source = hint;
-                            auto it = std::find(cycle.begin(), cycle.end(), source);
-                            to = it == cycle.end() || ++it == cycle.end() ? cycle.front() : *it;
+                            to = nextConversionLayout(text, available, cycle, hint);
                        }
                        result = convertTo(text, available, to, hint);
                    }
                }
                bool sent = false;
-                PasteProbe probe(config.writeLog && manual && result != text, text);
+                const bool requireReadback = tx.recoveredSelection() || snippet >= 0;
+                PasteProbe probe(((config.writeLog && manual) || requireReadback) && result != text, text, target);
+                if (requireReadback && result != text && probe.status != L"ready")
+                {
+                    reason = snippet >= 0 ? L"snippet-verification-unavailable" : L"recovered-selection-unavailable";
+                    std::lock_guard lock(stateMutex);
+                    last.reset();
+                    run.reset();
+                    return;
+                }
                diagnosticEvent(L"Conversion source=" + std::to_wstring(hint) + L" target=" + std::to_wstring(to) +
                    L" changed=" + std::to_wstring(result != text));
                if (result != text)
                    sent = tx.paste(textClip(result));
                else if (automatic && tx.valid())
                    chord(VK_RIGHT);
+                if (requireReadback && result != text && !sent)
+                {
+                    reason = snippet >= 0 ? L"snippet-paste-cancelled" : L"recovered-selection-paste-cancelled";
+                    std::lock_guard lock(stateMutex);
+                    last.reset();
+                    run.reset();
+                    return;
+                }
                if (sent || result == text)
                    autoSelected = false;
                reason = result == text ? L"conversion-unchanged" :
@@ -1228,19 +1512,48 @@ void App::transform(int command, int snippet)
                    reason = L"Conversion unchanged";
                    verification = L"calculated-result-equals-original";
                }
-                if (sent && manual && config.writeLog)
+                if (sent && ((manual && config.writeLog) || requireReadback))
                {
                    verification = probe.status;
                    if (tx.valid())
                    {
                        auto observed = probe.read((int)caretSteps(result));
+                        // A native Edit may silently ignore Ctrl+V while the clipboard is busy.
+                        // Retry once only with fresh native proof that the exact original range
+                        // is still selected. Never retry an unknown or changed editor state.
+                        if (observed && newlines(*observed) == newlines(text) && tx.nativeSelectionIs(text))
+                        {
+                            diagnosticEvent(L"Paste retry: native Edit still selects the unchanged original");
+                            if (tx.paste(textClip(result)) && tx.valid())
+                                observed = probe.read((int)caretSteps(result));
+                            else
+                                observed.reset();
+                        }
                        verification = probe.status;
                        if (observed && tx.valid())
                        {
                            actual = *observed;
                            reason = conversionReadbackOutcome(newlines(actual), newlines(text), newlines(result));
+                            if (newlines(actual) != newlines(result))
+                            {
+                                std::lock_guard lock(stateMutex);
+                                last.reset();
+                                run.reset();
+                                diagnosticEvent(L"Paste rejected by readback: previous result cleared; layout not switched");
+                                return;
+                            }
+                        }
+                        else
+                        {
+                            reason = L"Paste not verified";
+                            if (requireReadback)
+                            {
+                                std::lock_guard lock(stateMutex);
+                                last.reset();
+                                run.reset();
+                                return;
+                            }
                        }
-                        else reason = L"Paste not verified";
                    }
                    else verification = L"context-changed-after-paste";
                }
@@ -1296,6 +1609,7 @@ void App::transform(int command, int snippet)
 }
 void App::pasteEntry(std::wstring id, bool plain)
 {
+    if (historyService) { remoteHistory("paste", id, plain); return; }
    if (installingUpdate) return;
    if (!history || busy.exchange(true))
        return;
@@ -1317,10 +1631,20 @@ void App::pasteEntry(std::wstring id, bool plain)
            } reset{busy};
            try
            {
-                for (int i = 0; i < 20 && !modifiersReleased(); ++i)
+                // Foreground activation crosses a process boundary when the
+                // history UI closes. Let the destination finish activation,
+                // while retaining the same input-version cancellation guard.
+                for (int i = 0; i < 20 && inputVersion == version &&
+                     (!modifiersReleased() || GetForegroundWindow() != target); ++i)
                    Sleep(10);
                if (!modifiersReleased() || GetForegroundWindow() != target || inputVersion != version)
+                {
+                    log(L"History paste cancelled before transaction: foreground=" +
+                        std::to_wstring(GetForegroundWindow() == target) + L" modifiers=" +
+                        std::to_wstring(modifiersReleased()) + L" expectedVersion=" + std::to_wstring(version) +
+                        L" actualVersion=" + std::to_wstring(inputVersion.load()));
                    return;
+                }
                auto clip = history->load(id);
                if (plain)
                {
@@ -1330,7 +1654,7 @@ void App::pasteEntry(std::wstring id, bool plain)
                    clip = textClip(text);
                }
                Transaction tx(*this, target, version);
-                tx.paste(clip);
+                log(tx.paste(clip) ? L"History paste: simulated paste completed" : L"History paste cancelled before simulated paste");
            }
            catch (const std::exception &e)
            {
@@ -1361,7 +1685,19 @@ void App::captureHistory()
                for (auto &name : config.excluded)
                    if (lower(name) == lower(app))
                        return;
-                auto clip = readClipboard(window, (size_t)config.maxImageMiB * 1024 * 1024);
+                if (IsClipboardFormatAvailable(CF_DIB) || IsClipboardFormatAvailable(CF_DIBV5) ||
+                    IsClipboardFormatAvailable(CF_BITMAP) ||
+                    IsClipboardFormatAvailable(RegisterClipboardFormatW(L"PNG")))
+                {
+                    if (history->captureImage(sequence, app, config))
+                    {
+                        scheduleHistoryOcr(config);
+                        PostMessageW(window, HistoryMessage, 0, 0);
+                    }
+                    return;
+                }
+                auto clip = readClipboard(window, (size_t)config.maxImageMiB * 1024 * 1024,
+                                          ClipboardRead::WithoutImages, sequence);
                if (sequence != GetClipboardSequenceNumber())
                    return;
                for (auto &f : clip.formats)
@@ -1380,6 +1716,7 @@ void App::captureHistory()
 }
 void App::recognizeEntry(std::wstring id)
 {
+    if (historyService) { remoteHistory("ocr", id); return; }
    if (!history || busy.exchange(true))
        return;
    auto sequence = GetClipboardSequenceNumber();
@@ -1398,7 +1735,9 @@ void App::recognizeEntry(std::wstring id)
            try
            {
                auto cached = history->ocrText(id, ocrProfile(config));
-                auto text = cached ? *cached : recognizeText(history->load(id), config);
+                auto text = cached ? *cached : history->recognizeImage(id, config, [this] {
+                    std::lock_guard lock(jobsMutex); return stop;
+                });
                if (!cached) history->saveOcr(id, text, config);
                if (text.empty())
                {
@@ -1423,32 +1762,33 @@ void App::recognizeEntry(std::wstring id)
 void App::trayMenu()
 {
    HMENU menu = CreatePopupMenu();
-    AppendMenuW(menu, MF_STRING, 10, L"Clipboard history");
-    AppendMenuW(menu, MF_STRING, 24, L"Capture screen region…");
-    AppendMenuW(menu, MF_STRING, 11, L"Settings…");
+    AppendMenuW(menu, MF_STRING, 10, L"Clipboard &history");
+    AppendMenuW(menu, MF_STRING, 24, L"&Capture screen region…");
+    AppendMenuW(menu, MF_STRING, 11, L"&Settings…");
    SetMenuDefaultItem(menu, 11, FALSE);
-    AppendMenuW(menu, MF_STRING, 12, L"Snippets…");
-    AppendMenuW(menu, MF_STRING, 13, L"Keyboard shortcuts…");
+    AppendMenuW(menu, MF_STRING, 12, L"S&nippets…");
+    AppendMenuW(menu, MF_STRING, 13, L"&Keyboard shortcuts…");
    AppendMenuW(menu, MF_SEPARATOR, 0, nullptr);
-    AppendMenuW(menu, MF_STRING | (settings.awake ? MF_CHECKED : 0), 14, L"Keep screen awake");
+    AppendMenuW(menu, MF_STRING | (settings.awake ? MF_CHECKED : 0), 14, L"Keep screen a&wake");
    HMENU pause = CreatePopupMenu();
-    AppendMenuW(pause, MF_STRING, 20, L"Resume");
-    AppendMenuW(pause, MF_STRING, 21, L"10 minutes");
-    AppendMenuW(pause, MF_STRING, 22, L"1 hour");
-    AppendMenuW(pause, MF_STRING, 23, L"Until restart");
-    AppendMenuW(menu, MF_POPUP, (UINT_PTR)pause, L"Pause clipboard history");
-    AppendMenuW(menu, MF_STRING, 15, L"Open data folder");
-    AppendMenuW(menu, MF_STRING, 18, L"View log…");
+    AppendMenuW(pause, MF_STRING, 20, L"&Resume");
+    AppendMenuW(pause, MF_STRING, 21, L"&10 minutes");
+    AppendMenuW(pause, MF_STRING, 22, L"1 &hour");
+    AppendMenuW(pause, MF_STRING, 23, L"&Until restart");
+    AppendMenuW(menu, MF_POPUP, (UINT_PTR)pause, L"&Pause clipboard history");
+    AppendMenuW(menu, MF_STRING, 15, L"&Open data folder");
+    AppendMenuW(menu, MF_STRING, 18, L"View &log…");
    AppendMenuW(menu, MF_STRING | (updateRunning ? MF_GRAYED : 0), 19,
-                updateRunning ? L"Update (checking / preparing…)" :
-                availableUpdate.empty() ? L"Update" : L"Update (new version available)");
+                updateRunning ? L"&Update (checking / preparing…)" :
+                availableUpdate.empty() ? L"&Update" : L"&Update (new version available)");
    AppendMenuW(menu, MF_SEPARATOR, 0, nullptr);
-    AppendMenuW(menu, MF_STRING, 16, L"About KSwitcher");
-    AppendMenuW(menu, MF_STRING, 17, L"Exit");
+    AppendMenuW(menu, MF_STRING, 16, L"&About KSwitcher");
+    AppendMenuW(menu, MF_STRING, 17, L"E&xit");
    POINT pt;
    GetCursorPos(&pt);
    pasteTarget = GetForegroundWindow();
    SetForegroundWindow(window);
+    showMenuAccessKeys(menu);
    int cmd = TrackPopupMenu(menu, TPM_RETURNCMD | TPM_RIGHTBUTTON, pt.x, pt.y, 0, window, nullptr);
    DestroyMenu(menu);
    PostMessageW(window, WM_NULL, 0, 0);
@@ -1547,7 +1887,37 @@ LRESULT CALLBACK App::windowProc(HWND hwnd, UINT msg, WPARAM wp, LPARAM lp)
    auto *app = current;
    if (!app)
        return DefWindowProcW(hwnd, msg, wp, lp);
-    if (msg == app->taskbarCreated && app->taskbarCreated)
+    if (app->historyService) {
+        if (msg == HistoryHostShow || msg == HistoryHostRefresh) {
+            try {
+                app->history->reload();
+                if (msg == HistoryHostShow) showHistory(*app);
+                else if (IsWindowVisible(app->historyWindow)) refreshHistory(*app);
+            } catch (const std::exception &e) { app->report(wide(e.what())); }
+            return 0;
+        }
+        if (msg == WM_TIMER) {
+            if (!IsWindow(app->historyService)) PostMessageW(hwnd, WM_CLOSE, 0, 0);
+            return 0;
+        }
+        if (msg == WM_CLOSE) {
+            EnumThreadWindows(GetCurrentThreadId(), [](HWND child, LPARAM) -> BOOL {
+                wchar_t name[64]{}; GetClassNameW(child, name, 64);
+                if (std::wstring(name) == L"KSwitcher.Entry" || std::wstring(name) == L"KSwitcher.History")
+                    DestroyWindow(child);
+                return TRUE;
+            }, 0);
+            DestroyWindow(hwnd);
+            return 0;
+        }
+        if (msg == WM_DESTROY) { PostQuitMessage(0); return 0; }
+        if (msg == ErrorMessage) {
+            std::unique_ptr<std::wstring> text(reinterpret_cast<std::wstring *>(lp));
+            MessageBoxW(app->historyWindow, text->c_str(), L"Clipboard history", MB_OK | MB_ICONWARNING);
+            return 0;
+        }
+    }
+    if (!app->historyService && msg == app->taskbarCreated && app->taskbarCreated)
    {
        app->addTray();
        return 0;
@@ -1611,7 +1981,9 @@ LRESULT CALLBACK App::windowProc(HWND hwnd, UINT msg, WPARAM wp, LPARAM lp)
        app->replayTyping();
        return 0;
    case TrayMessage:
-        if (LOWORD(lp) == WM_CONTEXTMENU)
+        if (LOWORD(lp) == NIN_BALLOONUSERCLICK)
+            showLogs(*app);
+        else if (LOWORD(lp) == WM_CONTEXTMENU)
            app->trayMenu();
        else if (LOWORD(lp) == WM_LBUTTONDBLCLK)
            // The shell still owns the mouse gesture on the second button-down.
@@ -1661,6 +2033,7 @@ LRESULT CALLBACK App::windowProc(HWND hwnd, UINT msg, WPARAM wp, LPARAM lp)
    case WM_COPYDATA:
    {
        auto *data = (COPYDATASTRUCT *)lp;
+        if (data && data->dwData == HistoryRequest) return app->historyRequest((HWND)wp, *data);
        if (data && data->dwData >= ConfigRead && data->dwData < ConfigEnd)
        {
            if (app->installingUpdate) return FALSE;
@@ -1675,6 +2048,20 @@ LRESULT CALLBACK App::windowProc(HWND hwnd, UINT msg, WPARAM wp, LPARAM lp)
        return TRUE;
    }
    case WM_TIMER:
+        if (wp == 6)
+        {
+            if (app->notificationRegistration && WaitForSingleObject(app->notificationRegistration, 0) == WAIT_OBJECT_0)
+            {
+                DWORD code = ERROR_GEN_FAILURE;
+                GetExitCodeProcess(app->notificationRegistration, &code);
+                if (code) log(L"Screenshot notification registration helper failed: " + std::to_wstring(code));
+                CloseHandle(app->notificationRegistration);
+                app->notificationRegistration = nullptr;
+            }
+            app->releaseIdleMemory(GetTickCount64());
+            app->pollSync();
+            return 0;
+        }
        if (wp == 5)
        {
            // After the initial 5-second check, repeat while the resident stays open.
@@ -1733,7 +2120,7 @@ int App::execute()
    WNDCLASSW cls{};
    cls.hInstance = instance;
    cls.lpfnWndProc = windowProc;
-    cls.lpszClassName = L"KSwitcher.Main";
+    cls.lpszClassName = historyService ? HistoryHostClass : L"KSwitcher.Main";
    cls.hIcon = LoadIconW(instance, MAKEINTRESOURCEW(IDI_KSWITCHER));
    RegisterClassW(&cls);
    window = CreateWindowExW(WS_EX_TOOLWINDOW, cls.lpszClassName, L"KSwitcher", WS_POPUP, 0, 0, 0, 0, nullptr,
@@ -1767,6 +2154,30 @@ int App::execute()
            }
            CoUninitialize();
        });
+    if (historyService) {
+        try {
+            auto bytes = unprotect(readFile(data / L"history-view.bin", 4 * 1024 * 1024));
+            auto state = HistoryJson::parse(bytes);
+            historySelection = wide(state.value("selection", std::string{}));
+            historyTop = wide(state.value("top", std::string{}));
+            historyQuery = wide(state.value("query", std::string{}));
+            historyPinnedOnly = state.value("pinnedOnly", false);
+        } catch (...) {}
+        showHistory(*this);
+        remoteHistory("ready", std::to_wstring(reinterpret_cast<uintptr_t>(historyWindow)));
+        SetTimer(window, 1, 1000, nullptr);
+        MSG message{};
+        while (GetMessageW(&message, nullptr, 0, 0) > 0) {
+            if (message.message == WM_KEYDOWN && message.wParam == VK_ESCAPE && historyWindow &&
+                (message.hwnd == historyWindow || IsChild(historyWindow, message.hwnd))) {
+                SendMessageW(historyWindow, WM_CLOSE, 0, 0);
+                continue;
+            }
+            if (historyWindow && message.message == WM_SYSCHAR && IsDialogMessageW(historyWindow, &message)) continue;
+            TranslateMessage(&message); DispatchMessageW(&message);
+        }
+        return int(message.wParam);
+    }
    keyboardHook = SetWindowsHookExW(WH_KEYBOARD_LL, keyProc, instance, 0);
    mouseHook = SetWindowsHookExW(WH_MOUSE_LL, mouseProc, instance, 0);
    registerHotkeys(settings);
@@ -1777,6 +2188,7 @@ int App::execute()
    scheduleHistoryOcr(settings);
    addTray();
    SetTimer(window, 1, 60000, nullptr);
+    if (!smoke) SetTimer(window, 6, 1000, nullptr);
    SetThreadExecutionState(ES_CONTINUOUS |
                            (settings.awake ? (ES_DISPLAY_REQUIRED | ES_SYSTEM_REQUIRED) : 0));
    if (!registrationWarning.empty())
@@ -1789,7 +2201,7 @@ int App::execute()
        log(std::wstring(L"Update completed; running version ") + AppVersion);
    if (startCommand)
        PostMessageW(window, WM_HOTKEY, startCommand, 0);
-    try { registerScreenshotNotifications(); }
+    try { notificationRegistration = startScreenshotNotificationRegistration(); }
    catch(const std::exception &e) { log(L"Screenshot notification registration: "+wide(e.what())); }
    auto screenshotActivation=startScreenshotActivationListener();
    MSG msg;
@@ -1801,6 +2213,9 @@ int App::execute()
            if (popup != settingsWindow && IsDialogMessageW(popup, &msg))
                continue;
        }
+        // Preserve history-specific Enter/Shift+Enter and Ctrl+digit handling.
+        if (!isolateHistory && historyWindow && msg.message == WM_SYSCHAR && IsDialogMessageW(historyWindow, &msg))
+            continue;
        if (settingsWindow && IsDialogMessageW(settingsWindow, &msg))
            continue;
        if (snippetsWindow && IsDialogMessageW(snippetsWindow, &msg))
@@ -2,6 +2,7 @@
 #include "autocorrect.h"
 #include "storage.h"
 #include "update.h"
+#include "sync.h"
 #include <atomic>
 #include <condition_variable>
 #include <deque>
@@ -32,6 +33,11 @@ class App
 {
  public:
    HWND window{}, historyWindow{}, settingsWindow{}, snippetsWindow{};
+    HWND historyService{}; // Non-null only in the short-lived history UI process.
+    bool isolateHistory{};
+    unsigned historyEntryWindows{};
+    std::wstring historySelection, historyTop, historyQuery;
+    bool historyPinnedOnly{};
    HINSTANCE instance{};
    std::filesystem::path data;
    std::vector<Layout> layouts;
@@ -54,7 +60,7 @@ class App
    bool smoke{};
    int startCommand{};
    std::wstring updateStartupEvent;
-    App(HINSTANCE, bool = false, const std::filesystem::path &dataRoot = {});
+    App(HINSTANCE, bool = false, const std::filesystem::path &dataRoot = {}, HWND historyService = nullptr);
    ~App();
    int execute();
    void dispatch(int);
@@ -71,6 +77,11 @@ class App
    void applySettings(const Settings &);
    void reloadLayouts();
    void clearHistory();
+    void openHistoryProcess();
+    void refreshHistoryProcess();
+    void remoteHistory(const char *action, const std::wstring &id = {}, bool plain = false);
+    LRESULT historyRequest(HWND, const COPYDATASTRUCT &);
+    void saveHistoryView(const std::wstring &, const std::wstring &, const std::wstring &, bool);
    void clearLog(bool previous);
    void setHotkeyCapture(HWND);
    bool isHotkey(DWORD, UINT);
@@ -78,15 +89,21 @@ class App
    bool handleKeyboard(const KBDLLHOOKSTRUCT &, bool down, UINT modifiers);
    void resetInput();
    void checkUpdate(bool interactive, bool install = false, const std::wstring &version = {});
+    std::wstring syncCommand(int action = 0, const std::vector<SyncChoice> &choices = {});
+    Bytes syncConflictData();
+    void pollSync();
    static App *current;

  private:
    friend struct InputRegressionAccess;
+    void releaseIdleMemory(ULONGLONG now);
    HHOOK keyboardHook{}, mouseHook{};
+    HANDLE historyProcess{};
    std::mutex jobsMutex;
    std::condition_variable jobsReady;
    std::deque<std::function<void()>> jobs;
    std::thread worker;
+    HANDLE notificationRegistration{};
    std::thread historySearchWorker;
    std::condition_variable historySearchReady;
    std::function<void()> pendingHistorySearch;
@@ -96,6 +113,16 @@ class App
    Settings historyOcrSettings;
    void scheduleHistoryOcr(const Settings &);
    std::thread updateWorker;
+    std::thread syncWorker;
+    std::atomic<bool> syncDone{false};
+    bool syncRunning{};
+    ULONGLONG nextSync{}, syncRetryAfter{};
+    SyncResult syncResult;
+    SyncConfig syncConnection;
+    SyncConfig conflictConnection;
+    std::vector<SyncConflict> pendingSyncConflicts;
+    Bytes syncSnapshot;
+    std::wstring syncStatus = L"Not connected.";
    bool updateRunning{}, installingUpdate{};
    std::wstring availableUpdate, notifiedUpdate;
    bool (*updateNotifier)(const std::wstring &){};
@@ -116,6 +143,7 @@ class App
    void replayTyping();
    static LRESULT CALLBACK windowProc(HWND, UINT, WPARAM, LPARAM);
    static LRESULT CALLBACK keyProc(int, WPARAM, LPARAM);
+    static LRESULT keyboardAfterHooks(int, WPARAM, LPARAM, LRESULT);
    static LRESULT CALLBACK mouseProc(int, WPARAM, LPARAM);
 };
 void showHistory(App &, bool visible = true);
@@ -0,0 +1,100 @@
+// History UI has no clipboard listener or hooks. The resident remains the only writer.
+namespace {
+constexpr ULONG_PTR HistoryRequest = 0x4b530200;
+constexpr UINT HistoryHostShow = WM_APP + 71, HistoryHostRefresh = WM_APP + 72;
+constexpr wchar_t HistoryHostClass[] = L"KSwitcher.HistoryHost";
+using HistoryJson = nlohmann::json;
+HWND historyController(HANDLE process)
+{
+    if (!process || WaitForSingleObject(process, 0) == WAIT_OBJECT_0) return nullptr;
+    auto window = FindWindowW(HistoryHostClass, nullptr);
+    DWORD pid{}; GetWindowThreadProcessId(window, &pid);
+    return pid == GetProcessId(process) ? window : nullptr;
+}
+}
+void App::openHistoryProcess()
+{
+    auto foreground = GetForegroundWindow();
+    if (foreground != window && foreground != historyWindow) pasteTarget = foreground;
+    if (historyProcess && WaitForSingleObject(historyProcess, 0) == WAIT_OBJECT_0) {
+        CloseHandle(historyProcess); historyProcess = nullptr; historyWindow = nullptr;
+    }
+    if (historyProcess) {
+        if (auto host = historyController(historyProcess)) {
+            AllowSetForegroundWindow(GetProcessId(historyProcess));
+            PostMessageW(host, HistoryHostShow, 0, 0);
+        }
+        return;
+    }
+    auto path = executable();
+    auto command = L"\"" + path + L"\" --history-host=" + std::to_wstring(reinterpret_cast<uintptr_t>(window));
+    STARTUPINFOW startup{sizeof(startup)};
+    startup.dwFlags = STARTF_USESHOWWINDOW; startup.wShowWindow = SW_HIDE;
+    PROCESS_INFORMATION child{};
+    if (!CreateProcessW(path.c_str(), command.data(), nullptr, nullptr, FALSE, CREATE_NO_WINDOW,
+                        nullptr, std::filesystem::path(path).parent_path().c_str(), &startup, &child))
+        throw std::runtime_error("Cannot start clipboard history window");
+    CloseHandle(child.hThread);
+    historyProcess = child.hProcess;
+    AllowSetForegroundWindow(child.dwProcessId);
+}
+void App::refreshHistoryProcess()
+{
+    if (auto host = historyController(historyProcess)) PostMessageW(host, HistoryHostRefresh, 0, 0);
+}
+void App::remoteHistory(const char *action, const std::wstring &id, bool plain)
+{
+    if (!historyService || !configurationPeer(historyService, L"KSwitcher.exe"))
+        throw std::runtime_error("KSwitcher has stopped. Reopen clipboard history.");
+    auto text = HistoryJson{{"action", action}, {"id", utf8(id)}, {"plain", plain}}.dump();
+    if (std::string_view(action) == "paste") {
+        DWORD residentPid{}; GetWindowThreadProcessId(historyService, &residentPid);
+        AllowSetForegroundWindow(residentPid);
+    }
+    COPYDATASTRUCT message{HistoryRequest, DWORD(text.size()), text.data()};
+    DWORD_PTR result{};
+    if (!SendMessageTimeoutW(historyService, WM_COPYDATA, reinterpret_cast<WPARAM>(window),
+                             reinterpret_cast<LPARAM>(&message), SMTO_ABORTIFHUNG | SMTO_ERRORONEXIT,
+                             15000, &result) || result != 1)
+        throw std::runtime_error("KSwitcher could not complete the history request. Reopen history and retry.");
+}
+LRESULT App::historyRequest(HWND sender, const COPYDATASTRUCT &message)
+{
+    DWORD pid{}; GetWindowThreadProcessId(sender, &pid);
+    if (!historyProcess || pid != GetProcessId(historyProcess) ||
+        !configurationPeer(sender, L"KSwitcher.exe") || message.cbData > 4096 ||
+        !message.cbData || !message.lpData || installingUpdate) return FALSE;
+    try {
+        const auto *first = static_cast<const char *>(message.lpData);
+        auto job = HistoryJson::parse(first, first + message.cbData);
+        auto action = job.at("action").get<std::string>();
+        auto id = wide(job.at("id").get<std::string>());
+        if (id.size() > 128) return FALSE;
+        if (action == "ready") {
+            auto ui = reinterpret_cast<HWND>(uintptr_t(std::stoull(id)));
+            DWORD uiPid{}; GetWindowThreadProcessId(ui, &uiPid);
+            wchar_t name[64]{}; GetClassNameW(ui, name, 64);
+            if (uiPid != pid || std::wstring(name) != L"KSwitcher.History") return FALSE;
+            historyWindow = ui;
+        } else if (action == "paste") {
+            if (busy || !history) return FALSE;
+            pasteEntry(id, job.at("plain").get<bool>());
+        } else if (action == "ocr") {
+            if (busy || !history) return FALSE;
+            recognizeEntry(id);
+        } else if (action == "clear") clearHistory();
+        else if (action == "pin" || action == "remove") {
+            if (busy || !history) return FALSE;
+            if (action == "pin") history->pin(id); else history->remove(id);
+        } else return FALSE;
+        return TRUE;
+    } catch (...) { return FALSE; }
+}
+void App::saveHistoryView(const std::wstring &selection, const std::wstring &top, const std::wstring &query, bool pinnedOnly)
+{
+    if (!historyService) return;
+    try {
+        auto text = HistoryJson{{"selection", utf8(selection)}, {"top", utf8(top)}, {"query", utf8(query)}, {"pinnedOnly", pinnedOnly}}.dump();
+        atomicWrite(data / L"history-view.bin", protect(Bytes(text.begin(), text.end())));
+    } catch (...) {} // Closing the UI must still release its process if state cannot be saved.
+}
@@ -0,0 +1,101 @@
+// Included by app.cpp; all App mutations happen on its window thread.
+Bytes App::syncConflictData()
+{
+    if (loadSyncConfig(data) != conflictConnection) return encodeSyncConflicts({});
+    return encodeSyncConflicts(pendingSyncConflicts);
+}
+std::wstring App::syncCommand(int action, const std::vector<SyncChoice> &choices)
+{
+    if (action == 0) return syncStatus;
+    if (syncRunning) return L"Synchronization is already running.";
+    auto c = loadSyncConfig(data);
+    if (!c.enabled) return syncStatus = L"Synchronization is disabled.";
+    validateSyncConfig(c);
+    if (action == 4 && (c != conflictConnection || choices.empty()))
+        throw std::runtime_error("Connection changed or no choices selected. Sync again.");
+    if (busy) return L"Wait for the current text operation to finish.";
+    syncRetryAfter = 0; // Explicit retries may bypass the automatic error backoff.
+    if (syncWorker.joinable()) syncWorker.join();
+    syncConnection = c;
+    syncSnapshot = encodeSettings(settings);
+    auto snapshot = settings;
+    auto availableLayouts = layouts;
+    syncRunning = true;
+    syncDone = false;
+    syncStatus = L"Connecting to OpenBao...";
+    nextSync = GetTickCount64() + SyncIntervalMs;
+    try
+    {
+        syncWorker = std::thread([this, c, snapshot, availableLayouts, action, choices] {
+            SyncResult result;
+            try
+            {
+                auto provider = makeSyncProvider(c);
+                // An explicit choice also repairs a missing/corrupt local baseline.
+                auto base = action == 1 || action == 4 ? loadSyncBase(data, c) : Bytes{};
+                result = synchronize(*provider, base, sharedSyncSettings(snapshot),
+                    action == 2 ? SyncAction::Download : action == 3 ? SyncAction::Upload : SyncAction::Automatic,
+                    [&](const Bytes &b) { restoreSyncSettings(b, snapshot, availableLayouts, c.keepLocalLayouts); }, choices,
+                    c.keepLocalLayouts);
+                if (result.success && c.keepLocalLayouts)
+                    result.status += L" Partial sync: this PC's layouts and their shortcuts were kept; server layouts were preserved.";
+            }
+            catch (const nlohmann::json::exception &) { result.status = L"Invalid sync data or server response."; }
+            catch (const std::exception &e) { result.status = wide(e.what()); }
+            syncResult = std::move(result);
+            syncDone.store(true);
+        });
+    }
+    catch (...) { syncRunning = false; Bytes().swap(syncSnapshot); syncResult = {}; throw; }
+    return syncStatus;
+}
+void App::pollSync()
+{
+    try
+    {
+        if (syncRunning && syncDone.load())
+        {
+            if (busy) return;
+            syncWorker.join();
+            // Own completed payloads locally so every return/exception releases them.
+            auto result = std::exchange(syncResult, SyncResult{});
+            auto snapshot = std::exchange(syncSnapshot, Bytes{});
+            syncRunning = false;
+            syncDone = false;
+            syncStatus = result.status;
+            if (result.success)
+            {
+                if (loadSyncConfig(data) != syncConnection || encodeSettings(settings) != snapshot)
+                {
+                    syncStatus = L"Local settings or connection changed during sync. Checking again shortly.";
+                    nextSync = GetTickCount64() + 2000;
+                    return;
+                }
+                auto next = restoreSyncSettings(result.settings, settings, layouts, syncConnection.keepLocalLayouts);
+                if (encodeSettings(next) != snapshot)
+                {
+                    atomicWrite(data / L"settings-before-sync.bin", protect(snapshot));
+                    applySettings(next);
+                }
+                saveSyncBase(data, syncConnection, result.base.empty() ? result.settings : result.base);
+                pendingSyncConflicts = std::move(result.conflicts);
+                conflictConnection = syncConnection;
+                SYSTEMTIME time{}; GetLocalTime(&time);
+                wchar_t stamp[32]{};
+                swprintf(stamp, std::size(stamp), L" (%02u:%02u:%02u)", time.wHour, time.wMinute, time.wSecond);
+                syncStatus += stamp;
+            }
+            // Back off after errors (including bad credentials) instead of repeatedly
+            // hitting userpass lockout. The explicit Sync button remains available.
+            syncRetryAfter = result.success ? 0 : GetTickCount64() + 15 * 60000;
+            nextSync = result.success ? GetTickCount64() + SyncIntervalMs : syncRetryAfter;
+        }
+        if (!syncRunning && GetTickCount64() >= nextSync)
+        {
+            nextSync = GetTickCount64() + SyncIntervalMs;
+            if (loadSyncConfig(data).enabled) syncCommand(1);
+        }
+    }
+    catch (const nlohmann::json::exception &) { syncStatus = L"Invalid local sync configuration or cached profile."; nextSync = GetTickCount64() + SyncIntervalMs; }
+    catch (const std::exception &e) { syncStatus = wide(e.what()); nextSync = GetTickCount64() + SyncIntervalMs; }
+}
@@ -42,82 +42,160 @@ bool safeAutoWord(const std::wstring &word, int minimumLength)
    auto small = lower(word);
    return word == small || (word.substr(1) == small.substr(1) && word != upper(word));
 }
-std::string_view AutoCorrector::Dictionary::word(size_t index) const
+namespace {
+constexpr size_t DictionaryBlockWords = 32;
+}
+std::string_view AutoCorrector::Dictionary::word(size_t block) const
 {
-    auto start = offsets[index];
-    auto end = bytes.find('\t', start);
-    return std::string_view(bytes).substr(start, end - start);
+    size_t start = offsets[block];
+    // Every block starts with a complete word (zero shared prefix).
+    size_t length = static_cast<unsigned char>(bytes[start++]) & 15;
+    if (length == 15) length = static_cast<unsigned char>(bytes[start++]);
+    return std::string_view(bytes).substr(start, length);
 }
 AutoCorrector::Dictionary::Dictionary(const std::filesystem::path &path)
 {
-    auto raw = readFile(path, 2 * 1024 * 1024);
-    bytes.assign(raw.begin(), raw.end());
-    for (size_t start = 0; start < bytes.size();)
+    const auto raw = readFile(path, 2 * 1024 * 1024);
+    const std::string_view source(reinterpret_cast<const char *>(raw.data()), raw.size());
+    std::vector<uint32_t> lines;
+    lines.reserve(std::count(source.begin(), source.end(), '\n') + 1);
+    for (size_t start = 0; start < source.size();)
    {
-        auto end = bytes.find('\n', start);
-        if (end == bytes.npos)
-            end = bytes.size();
-        auto tab = bytes.find('\t', start);
-        if (tab == bytes.npos || tab >= end || tab == start || tab - start > 160)
+        auto end = source.find('\n', start);
+        if (end == source.npos) end = source.size();
+        auto tab = source.find('\t', start);
+        if (tab == source.npos || tab >= end || tab == start || tab - start > 160)
            throw std::runtime_error("Invalid auto-correction dictionary");
        int rank{};
-        auto rankEnd = end > tab + 1 && bytes[end - 1] == '\r' ? end - 1 : end;
-        auto parse = std::from_chars(bytes.data() + tab + 1, bytes.data() + rankEnd, rank);
-        if (parse.ec != std::errc() || parse.ptr != bytes.data() + rankEnd || rank <= 0)
+        auto rankEnd = end > tab + 1 && source[end - 1] == '\r' ? end - 1 : end;
+        auto parse = std::from_chars(source.data() + tab + 1, source.data() + rankEnd, rank);
+        if (parse.ec != std::errc() || parse.ptr != source.data() + rankEnd || rank <= 0)
            throw std::runtime_error("Invalid dictionary rank");
-        offsets.push_back((uint32_t)start);
+        lines.push_back(static_cast<uint32_t>(start));
        start = end + 1;
    }
-    if (offsets.empty())
-        throw std::runtime_error("Empty auto-correction dictionary");
-    auto entry = [&](uint32_t offset) { return std::string_view(bytes).substr(offset, bytes.find('\t', offset) - offset); };
-    auto frequency = [&](uint32_t offset)
-    {
+    if (lines.empty()) throw std::runtime_error("Empty auto-correction dictionary");
+    auto entry = [&](uint32_t offset) { return source.substr(offset, source.find('\t', offset) - offset); };
+    auto frequency = [&](uint32_t offset) {
        int rank{};
        auto start = offset + entry(offset).size() + 1;
-        std::from_chars(bytes.data() + start, bytes.data() + bytes.size(), rank);
+        std::from_chars(source.data() + start, source.data() + source.size(), rank);
        return rank;
    };
-    std::sort(offsets.begin(), offsets.end(), [&](uint32_t a, uint32_t b)
-              { return entry(a) == entry(b) ? frequency(a) < frequency(b) : entry(a) < entry(b); });
-    offsets.erase(std::unique(offsets.begin(), offsets.end(), [&](uint32_t a, uint32_t b)
-                              { return entry(a) == entry(b); }), offsets.end());
-    offsets.shrink_to_fit();
-    bytes.shrink_to_fit();
+    std::sort(lines.begin(), lines.end(), [&](uint32_t a, uint32_t b) {
+        return entry(a) == entry(b) ? frequency(a) < frequency(b) : entry(a) < entry(b);
+    });
+    lines.erase(std::unique(lines.begin(), lines.end(), [&](uint32_t a, uint32_t b) {
+        return entry(a) == entry(b);
+    }), lines.end());
+    offsets.reserve((lines.size() + DictionaryBlockWords - 1) / DictionaryBlockWords);
+    std::string_view previous;
+    // Allocate the packed payload exactly once. Geometric growth and a final
+    // shrink otherwise leave discarded buffers in the resident process heap.
+    size_t packedSize = 0;
+    for (size_t i = 0; i < lines.size(); ++i)
+    {
+        auto current = entry(lines[i]);
+        size_t prefix = 0;
+        if (i % DictionaryBlockWords != 0)
+            while (prefix < std::min(previous.size(), current.size()) && previous[prefix] == current[prefix]) ++prefix;
+        auto suffix = current.size() - prefix;
+        packedSize += 1 + (prefix >= 15) + (suffix >= 15) + suffix + 2;
+        auto rank = static_cast<uint32_t>(frequency(lines[i]));
+        if (rank >= 65535)
+            do { ++packedSize; rank >>= 7; } while (rank);
+        previous = current;
+    }
+    bytes.reserve(packedSize);
+    previous = {};
+    for (size_t i = 0; i < lines.size(); ++i)
+    {
+        auto current = entry(lines[i]);
+        size_t prefix = 0;
+        if (i % DictionaryBlockWords == 0)
+            offsets.push_back(static_cast<uint32_t>(bytes.size()));
+        else
+            while (prefix < std::min(previous.size(), current.size()) && previous[prefix] == current[prefix]) ++prefix;
+        size_t suffix = current.size() - prefix;
+        bytes.push_back(static_cast<char>((std::min(prefix, size_t(15)) << 4) | std::min(suffix, size_t(15))));
+        if (prefix >= 15) bytes.push_back(static_cast<char>(prefix));
+        if (suffix >= 15) bytes.push_back(static_cast<char>(suffix));
+        bytes.append(current.substr(prefix));
+        auto rank = static_cast<uint32_t>(frequency(lines[i]));
+        auto shortRank = std::min(rank, uint32_t(65535));
+        bytes.push_back(static_cast<char>(shortRank & 255));
+        bytes.push_back(static_cast<char>(shortRank >> 8));
+        if (rank >= 65535)
+            do {
+                auto next = rank & 127;
+                rank >>= 7;
+                bytes.push_back(static_cast<char>(next | (rank ? 128 : 0)));
+            } while (rank);
+        previous = current;
+    }
 }
 int AutoCorrector::Dictionary::rank(const std::wstring &text) const
 {
    auto key = utf8(lower(text));
    size_t begin = 0, end = offsets.size();
+    // Find the last block whose first word is <= the search key.
    while (begin < end)
    {
        auto mid = begin + (end - begin) / 2;
-        if (word(mid) < key)
-            begin = mid + 1;
-        else
-            end = mid;
+        if (word(mid) <= key) begin = mid + 1;
+        else end = mid;
+    }
+    if (!begin) return 0;
+    size_t block = begin - 1;
+    size_t at = offsets[block];
+    const size_t limit = begin < offsets.size() ? offsets[begin] : bytes.size();
+    char decoded[160]; // The loader validates lengths; lookup never allocates a decoded word.
+    while (at < limit)
+    {
+        auto lengths = static_cast<unsigned char>(bytes[at++]);
+        size_t prefix = lengths >> 4, suffix = lengths & 15;
+        if (prefix == 15) prefix = static_cast<unsigned char>(bytes[at++]);
+        if (suffix == 15) suffix = static_cast<unsigned char>(bytes[at++]);
+        memcpy(decoded + prefix, bytes.data() + at, suffix);
+        at += suffix;
+        uint32_t rank = static_cast<unsigned char>(bytes[at]) |
+                        (uint32_t(static_cast<unsigned char>(bytes[at + 1])) << 8);
+        at += 2;
+        if (rank == 65535) {
+            rank = 0;
+            uint32_t shift = 0;
+            unsigned char part;
+            do {
+                part = static_cast<unsigned char>(bytes[at++]);
+                rank |= uint32_t(part & 127) << shift;
+                shift += 7;
+            } while (part & 128);
+        }
+        auto compared = std::string_view(decoded, size_t(prefix) + suffix).compare(key);
+        if (compared == 0) return static_cast<int>(rank);
+        if (compared > 0) return 0;
    }
-    if (begin == offsets.size() || word(begin) != key)
    return 0;
-    auto start = offsets[begin] + word(begin).size() + 1;
-    int rank{};
-    std::from_chars(bytes.data() + start, bytes.data() + bytes.size(), rank);
-    return rank;
 }
 void AutoCorrector::configure(const std::filesystem::path &folder, const std::vector<std::wstring> &wanted)
 {
    if (languages == wanted)
        return;
-    std::map<std::wstring, Dictionary> next;
+    std::map<std::wstring, std::shared_ptr<const Dictionary>> next;
    for (auto &lang : wanted)
    {
        if (lang != L"en" && lang != L"uk" && lang != L"ru")
            throw std::runtime_error("Unsupported dictionary language");
-        next.emplace(lang, Dictionary(folder / (lang + L".txt")));
+        next.emplace(lang, std::make_shared<const Dictionary>(folder / (lang + L".txt")));
    }
    dictionaries = std::move(next);
    languages = wanted;
 }
+void AutoCorrector::shareDictionaries(const AutoCorrector &source)
+{
+    dictionaries = source.dictionaries;
+    languages = source.languages;
+}
 void AutoCorrector::reject(std::wstring word, const Settings &settings)
 {
    while (!word.empty() && openingDelimiter(word.front(), settings))
@@ -132,7 +210,7 @@ size_t AutoCorrector::memoryBytes() const
 {
    size_t bytes = 0;
    for (auto &[language, d] : dictionaries)
-        bytes += d.bytes.capacity() + d.offsets.capacity() * sizeof(uint32_t);
+        bytes += d->bytes.capacity() + d->offsets.capacity() * sizeof(uint32_t);
    return bytes;
 }
 std::optional<AutoSuggestion> AutoCorrector::suggest(const std::wstring &typed, int source,
@@ -164,6 +242,24 @@ std::optional<AutoSuggestion> AutoCorrector::suggest(const std::wstring &typed,
    auto sourceLanguage = layoutLanguage(layouts[source]);
    if (!dictionaries.contains(sourceLanguage))
        return {};
+    const std::wstring alphabet = sourceLanguage == L"en" ? L"abcdefghijklmnopqrstuvwxyz" :
+        sourceLanguage == L"uk" ? L"абвгґдеєжзиіїйклмнопрстуфхцчшщьюя" : L"абвгдеёжзийклмнопрстуфхцчшщъыьэюя";
+    auto small = lower(word);
+    bool sameLanguage = safeAutoWord(word, settings.autoMinLength) &&
+        small.find_first_not_of(alphabet) == small.npos &&
+        std::find(settings.cycle.begin(), settings.cycle.end(), layouts[source].id) != settings.cycle.end();
+    auto sameLayout = [&](std::wstring text)
+    {
+        if (word != small) text[0] = upper(text.substr(0, 1))[0];
+        return AutoSuggestion{source, source, prefix + text + suffix};
+    };
+    if (settings.autoReplace && sameLanguage)
+    {
+        auto replacement = settings.autoReplacements.find(small);
+        if (replacement != settings.autoReplacements.end() &&
+            replacement->second.find_first_not_of(alphabet) == small.npos)
+            return sameLayout(replacement->second);
+    }
    auto personal = [&](const std::wstring &language, const std::wstring &candidate)
    {
        auto found = settings.autoWords.find(language);
@@ -173,7 +269,7 @@ std::optional<AutoSuggestion> AutoCorrector::suggest(const std::wstring &typed,
    };
    // Valid words from either selected language are never changed.
    for (auto &[language, d] : dictionaries)
-        if (d.rank(word) || personal(language, word))
+        if (d->rank(word) || personal(language, word))
            return {};
    std::optional<AutoSuggestion> candidate;
    std::optional<std::wstring> matchedText;
@@ -193,7 +289,7 @@ std::optional<AutoSuggestion> AutoCorrector::suggest(const std::wstring &typed,
        auto converted = convert(word, layouts[source], layouts[i], true);
        if (converted == word || !safeAutoWord(converted, settings.autoMinLength))
            continue;
-        int rank = personal(dictionary->first, converted) ? 1 : dictionary->second.rank(converted);
+        int rank = personal(dictionary->first, converted) ? 1 : dictionary->second->rank(converted);
        if (!rank)
            continue;
        if (matchedText && *matchedText != converted)
@@ -203,7 +299,54 @@ std::optional<AutoSuggestion> AutoCorrector::suggest(const std::wstring &typed,
            (!candidate || priority(i) < priority(candidate->target)))
            candidate = AutoSuggestion{source, i, prefix + converted + suffix};
    }
+    if (candidate || matchedText || !settings.autoTypos || !sameLanguage || word.size() < 4)
        return candidate;
+    // Generate only single edits. Stop at a second distinct dictionary hit,
+    // including rare hits: frequency limits must never hide ambiguity.
+    std::wstring found;
+    int foundRank = 0;
+    std::set<std::wstring> personalTargets;
+    if (auto it = settings.autoWords.find(sourceLanguage); it != settings.autoWords.end())
+        for (const auto &text : it->second) personalTargets.insert(lower(text));
+    auto consider = [&](const std::wstring &text)
+    {
+        if (text == small || text == found || text.size() < 4 || text.size() > 32) return true;
+        int rank = personalTargets.contains(text) ? 1 : dictionaries.at(sourceLanguage)->rank(text);
+        if (!rank) return true;
+        if (!found.empty()) return false;
+        found = text;
+        foundRank = rank;
+        return true;
+    };
+    for (size_t i = 0; i < small.size(); ++i)
+    {
+        auto text = small;
+        text.erase(i, 1);
+        if (!consider(text)) return {};
+        if (i + 1 < small.size())
+        {
+            text = small;
+            std::swap(text[i], text[i + 1]);
+            if (!consider(text)) return {};
+        }
+        for (wchar_t c : alphabet)
+        {
+            text = small;
+            text[i] = c;
+            if (!consider(text)) return {};
+        }
+    }
+    if (small.size() < 32)
+        for (size_t i = 0; i <= small.size(); ++i)
+            for (wchar_t c : alphabet)
+            {
+                auto text = small;
+                text.insert(i, 1, c);
+                if (!consider(text)) return {};
+            }
+    if (!found.empty() && (settings.autoMaxRank == 0 || foundRank <= settings.autoMaxRank))
+        return sameLayout(found);
+    return {};
 }
 int matchAutoInput(const Run &run, const std::wstring &text, const std::vector<Layout> &layouts,
                   const Layout &physical, const Settings &settings)
@@ -1,6 +1,7 @@
 #pragma once
 #include "platform.h"
 #include <map>
+#include <memory>
 #include <set>
 #include <string_view>
 namespace ks
@@ -18,23 +19,30 @@ int matchAutoInput(const Run &, const std::wstring &, const std::vector<Layout>
 bool autoCorrectionAllowed(HWND, const Settings &);
 class AutoCorrector
 {
+    friend struct AutoCorrectorRegressionAccess;
    struct Dictionary
    {
+        // Front-coded UTF-8 words in independently searchable blocks of 32.
+        // Prefix/suffix lengths share a byte (15 escapes to a full byte length).
+        // Ranks use two bytes; 65535 escapes to a varint for larger custom ranks.
        std::string bytes;
        std::vector<uint32_t> offsets;
        std::string_view word(size_t) const;
        explicit Dictionary(const std::filesystem::path &);
        int rank(const std::wstring &) const;
    };
-    std::map<std::wstring, Dictionary> dictionaries;
+    std::map<std::wstring, std::shared_ptr<const Dictionary>> dictionaries;
    std::vector<std::wstring> languages;
    std::set<std::wstring> rejected;

  public:
    void configure(const std::filesystem::path &, const std::vector<std::wstring> &);
+    // Share immutable dictionary storage, keeping each consumer's undo rejections private.
+    void shareDictionaries(const AutoCorrector &);
    std::optional<AutoSuggestion> suggest(const std::wstring &, int source, const std::vector<Layout> &,
                                          const Settings &) const;
    void reject(std::wstring word, const Settings & = {});
+    // Referenced dictionary payload, including shared storage (do not sum across consumers).
    size_t memoryBytes() const;
 };
 } // namespace ks
@@ -79,9 +79,10 @@ LRESULT CALLBACK controller(HWND window, UINT message, WPARAM wp, LPARAM lp)
 }
 // The configurator owns no history store, dictionaries, worker or input hooks.
 // All mutations are validated and committed by the resident process.
-App::App(HINSTANCE h, bool, const std::filesystem::path &) : instance(h)
+App::App(HINSTANCE h, bool, const std::filesystem::path &, HWND) : instance(h)
 {
    current = this;
+    data = dataDirectory();
    layouts = readLayouts();
 }
 App::~App()
@@ -110,6 +111,13 @@ void App::reloadLayouts()
    settings = decodeSettings(bytes, layouts);
 }
 void App::clearHistory() { request(*this, ConfigClearHistory); }
+Bytes App::syncConflictData() { return request(*this, ConfigSyncConflicts); }
+std::wstring App::syncCommand(int action, const std::vector<SyncChoice> &choices)
+{
+    auto result = action == 4 ? request(*this, ConfigSyncResolve, encodeSyncChoices(choices)) :
+        request(*this, ConfigSync, Bytes{static_cast<unsigned char>(action)});
+    return wide(std::string(result.begin(), result.end()));
+}
 void App::setHotkeyCapture(HWND field)
 {
    hotkeyCapture = field;
@@ -180,6 +188,12 @@ int runConfigurator(HINSTANCE instance, bool snippets, bool logs)
        if (app.settingsWindow && !IsWindowEnabled(app.settingsWindow))
        {
            HWND popup = GetLastActivePopup(app.settingsWindow);
+            while (!IsWindowEnabled(popup))
+            {
+                HWND next = GetLastActivePopup(popup);
+                if (next == popup) break;
+                popup = next;
+            }
            if (popup != app.settingsWindow && IsDialogMessageW(popup, &message)) continue;
        }
        if (app.settingsWindow && IsDialogMessageW(app.settingsWindow, &message)) continue;
@@ -40,6 +40,25 @@ LRESULT configurationRequest(App &app, HWND sender, const COPYDATASTRUCT &messag
    {
        switch (message.dwData)
        {
+        case ConfigSyncConflicts:
+            reply = app.syncConflictData();
+            break;
+        case ConfigSyncResolve:
+        {
+            if (!message.cbData) throw std::runtime_error("Empty conflict choices.");
+            auto first = static_cast<const unsigned char *>(message.lpData);
+            auto status = utf8(app.syncCommand(4, decodeSyncChoices(Bytes(first, first + message.cbData))));
+            reply.assign(status.begin(), status.end());
+            break;
+        }
+        case ConfigSync:
+        {
+            if (message.cbData != 1 || *static_cast<const unsigned char *>(message.lpData) > 3)
+                throw std::runtime_error("Invalid sync command.");
+            auto status = utf8(app.syncCommand(*static_cast<const unsigned char *>(message.lpData)));
+            reply.assign(status.begin(), status.end());
+            break;
+        }
        case ConfigSave:
        {
            if (app.busy) throw std::runtime_error("Wait for the current text operation to finish.");
@@ -5,7 +5,9 @@ namespace ks
 inline constexpr ULONG_PTR ConfigRead = 0x4b530100, ConfigSave = ConfigRead + 1,
    ConfigLayouts = ConfigRead + 2, ConfigClearHistory = ConfigRead + 3,
    ConfigCapture = ConfigRead + 4, ConfigLogs = ConfigRead + 5,
-    ConfigReply = ConfigRead + 6, ConfigClearLog = ConfigRead + 7, ConfigEnd = ConfigRead + 8;
+    ConfigReply = ConfigRead + 6, ConfigClearLog = ConfigRead + 7,
+    ConfigSync = ConfigRead + 8, ConfigSyncConflicts = ConfigRead + 9,
+    ConfigSyncResolve = ConfigRead + 10, ConfigEnd = ConfigRead + 11;
 inline constexpr size_t ConfigLimit = 8 * 1024 * 1024;
 bool configurationPeer(HWND, const wchar_t *filename);
 void launchConfiguration(App &, bool snippets = false, bool logs = false);
@@ -148,6 +148,26 @@ std::wstring convertTo(const std::wstring &text, const std::vector<Layout> &layo
    }
    return best < 0 ? text : convert(text, layouts[best], to);
 }
+int nextConversionLayout(const std::wstring &text, const std::vector<Layout> &layouts,
+                         const std::vector<int> &cycle, int hint)
+{
+    if (cycle.empty())
+        return -1;
+    int source = detect(text, layouts, hint);
+    if (source < 0)
+        source = hint;
+    auto it = std::find(cycle.begin(), cycle.end(), source);
+    size_t start = it == cycle.end() ? 0 : (size_t(it - cycle.begin()) + 1) % cycle.size();
+    // Compare every candidate with the original input, never an intermediate conversion.
+    // Bound the search so digits, whitespace and identical layouts cannot loop forever.
+    for (size_t offset = 0; offset < cycle.size(); ++offset)
+    {
+        int target = cycle[(start + offset) % cycle.size()];
+        if (target != source && convertTo(text, layouts, target, hint) != text)
+            return target;
+    }
+    return cycle[start];
+}
 std::wstring cycleCase(const std::wstring &text)
 {
    if (text == upper(text))
@@ -459,6 +479,14 @@ void Run::backspace(HWND w, ULONGLONG now)
        keys.pop_back();
    at = now;
 }
+int Run::matchSuffix(const std::wstring &text, const std::vector<Layout> &layouts, const Layout &physical) const
+{
+    if (text.empty() || text.size() >= keys.size() || overflow)
+        return -1;
+    Run tail = *this;
+    tail.keys = keys.substr(keys.size() - text.size());
+    return tail.match(text, layouts, physical);
+}
 int Run::match(const std::wstring &text, const std::vector<Layout> &layouts, const Layout &physical) const
 {
    if (text.size() != keys.size() || overflow)
@@ -24,12 +24,17 @@ std::wstring upper(std::wstring text);
 std::wstring convert(const std::wstring &, const Layout &, const Layout &, bool force = false);
 int detect(const std::wstring &, const std::vector<Layout> &, int preferred = -1);
 std::wstring convertTo(const std::wstring &, const std::vector<Layout> &, int target, int hint);
+int nextConversionLayout(const std::wstring &, const std::vector<Layout> &,
+                         const std::vector<int> &cycle, int hint);
 std::wstring cycleCase(const std::wstring &);
 std::wstring transliterate(const std::wstring &);
 struct Snippet
 {
    std::wstring trigger, text;
+    std::wstring id;
 };
+std::wstring snippetId(const Snippet &);
+std::wstring newSnippetId();
 struct Template
 {
    std::wstring text, suffix;
@@ -49,6 +54,8 @@ struct Settings
    bool recent = true, switchLayout = true, history = true, autostart = false, awake = false;
    bool elevatedAutostart = false;
    bool autoCorrect = false;
+    bool autoReplace = false, autoTypos = false;
+    std::map<std::wstring, std::wstring> autoReplacements;
    bool writeLog = true;
    bool screenshotAutoOpenEditor = false;
    bool useTesseract = false;
@@ -71,6 +78,7 @@ struct Settings
    std::vector<std::wstring> cycle, direct, directIds;
    std::vector<std::wstring> excluded{L"KeePass", L"KeePassXC", L"1Password", L"Bitwarden"};
    std::vector<Snippet> snippets;
+    std::vector<std::wstring> snippetTombstones;
 };
 // Consume repeats and key-up for intercepted chords, even if settings change.
 struct HotkeyHook
@@ -92,5 +100,6 @@ struct Run
    void record(wchar_t, HWND, HKL, ULONGLONG);
    void backspace(HWND, ULONGLONG);
    int match(const std::wstring &, const std::vector<Layout> &, const Layout &physical) const;
+    int matchSuffix(const std::wstring &, const std::vector<Layout> &, const Layout &physical) const;
 };
 } // namespace ks
@@ -37,7 +37,8 @@ inline std::vector<OperationLogRow> parseOperationLog(const std::wstring &conten
                    L"Operation: " + field("attempt") + L"\r\nResult: " + row.outcome +
                    L"\r\nVerification: " + field("verification") + L"\r\nElapsed: " +
                    std::to_wstring(j.value("elapsedMs", 0ULL)) + L" ms\r\n\r\nOriginal:\r\n" +
-                    field("original") + L"\r\n\r\nExpected result:\r\n" + field("expected") +
+                    field("original") + L"\r\n\r\nExpected selection:\r\n" + field("selectionExpected") +
+                    L"\r\n\r\nExpected result / verification target:\r\n" + field("expected") +
                    L"\r\n\r\nRead back:\r\n" + field("actual") + L"\r\n\r\nForeground unchanged: " +
                    (j.value("foregroundSame", false) ? L"yes" : L"no") + L"\r\nInput context unchanged: " +
                    (j.value("inputSame", false) ? L"yes" : L"no") + L"\r\nText truncated: " +
@@ -4,14 +4,28 @@
 #include <string>

 namespace ks {
+inline constexpr size_t HistoryThumbnailBudget = 1024 * 1024;
+inline constexpr size_t HistoryRichTextBudget = 256 * 1024;
 // Keep the visible working set even in unusually tall windows. Never evict a
 // visible preview to admit another visible preview: that creates a paint loop.
+template<class T, class Weight>
+void trimHistoryPreviews(std::map<std::wstring,T> &cache,
+                         const std::set<std::wstring> &visible, size_t limit,
+                         size_t byteLimit, Weight weight)
+{
+    size_t bytes = 0;
+    for (const auto &[id, value] : cache) bytes += weight(value);
+    for(auto it=cache.begin(); (cache.size()>limit || bytes>byteLimit) && it!=cache.end();)
+        if(!visible.contains(it->first)) {
+            bytes -= weight(it->second);
+            it=cache.erase(it);
+        }
+        else ++it;
+}
 template<class T>
 void trimHistoryPreviews(std::map<std::wstring,T> &cache,
                         const std::set<std::wstring> &visible, size_t limit=32)
 {
-    for(auto it=cache.begin(); cache.size()>limit && it!=cache.end();)
-        if(!visible.contains(it->first)) it=cache.erase(it);
-        else ++it;
+    trimHistoryPreviews(cache, visible, limit, 0, [](const T &) { return size_t{}; });
 }
 }
@@ -1,12 +1,27 @@
 #include "app.h"
 #include <shellapi.h>
 #include <shlobj.h>
+#include "configuration.h"
 int WINAPI wWinMain(HINSTANCE instance, HINSTANCE, PWSTR, int)
 {
    CoInitializeEx(nullptr, COINIT_APARTMENTTHREADED);
    int argc{};
    auto argv = CommandLineToArgvW(GetCommandLineW(), &argc);
    std::wstring arg = argc > 1 ? argv[1] : L"";
+    if (argc == 2 && arg.starts_with(L"--history-host=")) {
+        LocalFree(argv);
+        int result = 1;
+        try {
+            auto service = reinterpret_cast<HWND>(uintptr_t(std::stoull(arg.substr(15))));
+            wchar_t name[64]{}; GetClassNameW(service, name, 64);
+            if (std::wstring(name) != L"KSwitcher.Main" || !ks::configurationPeer(service, L"KSwitcher.exe"))
+                throw std::runtime_error("Invalid history service");
+            ks::App app(instance, true, {}, service);
+            result = app.execute();
+        } catch (...) {}
+        CoUninitialize();
+        return result;
+    }
    if (arg.starts_with(L"--configure-autostart="))
    {
        int result = 1;
@@ -72,6 +87,7 @@ int WINAPI wWinMain(HINSTANCE instance, HINSTANCE, PWSTR, int)
    try
    {
        ks::App app(instance, arg == L"--smoke-test");
+        app.isolateHistory = !app.smoke;
        if (arg.starts_with(L"--update-ready-event="))
            app.updateStartupEvent = arg.substr(std::wstring(L"--update-ready-event=").size());
        else if (!arg.empty() && arg != L"--smoke-test")
@@ -123,13 +123,16 @@ struct OcrStatics : IInspectable
 Pixels decodeImage(const Clip &clip, UINT maxWidth, UINT maxHeight)
 {
    Bytes encoded;
+    const Bytes *input = &encoded;
    for (const auto &f : clip.formats)
        if (f.name == L"PNG")
        {
-            encoded = f.data;
+            input = &f.data;
            break;
        }
-    if (encoded.empty())
+    if (input->empty())
+    {
+        input = &encoded;
        for (const auto &f : clip.formats)
            if ((f.id == CF_DIB || f.id == CF_DIBV5) && f.data.size() >= 40)
            {
@@ -146,19 +149,21 @@ Pixels decodeImage(const Clip &clip, UINT maxWidth, UINT maxHeight)
                file.bfType = 0x4d42;
                file.bfSize = (DWORD)(sizeof(file) + f.data.size());
                file.bfOffBits = (DWORD)offset;
-                encoded.resize(sizeof(file));
+                encoded.resize(sizeof(file) + f.data.size());
                memcpy(encoded.data(), &file, sizeof(file));
-                encoded.insert(encoded.end(), f.data.begin(), f.data.end());
+                memcpy(encoded.data() + sizeof(file), f.data.data(), f.data.size());
                break;
            }
-    if (encoded.empty())
+    }
+    if (input->empty())
        throw std::runtime_error("This clipboard item has no supported image");
    Com<IWICImagingFactory> wic;
    check(CoCreateInstance(CLSID_WICImagingFactory, nullptr, CLSCTX_INPROC_SERVER, IID_IWICImagingFactory,
                           (void **)wic.out()));
    Com<IWICStream> stream;
    check(wic->CreateStream(stream.out()));
-    check(stream->InitializeFromMemory(encoded.data(), (DWORD)encoded.size()));
+    // WIC decoding only reads the stream. The clip outlives every WIC object here.
+    check(stream->InitializeFromMemory(const_cast<BYTE *>(input->data()), (DWORD)input->size()));
    Com<IWICBitmapDecoder> decoder;
    check(wic->CreateDecoderFromStream(stream.p, nullptr, WICDecodeMetadataCacheOnLoad, decoder.out()));
    Com<IWICBitmapFrameDecode> frame;
@@ -186,6 +191,43 @@ Pixels decodeImage(const Clip &clip, UINT maxWidth, UINT maxHeight)
    check(converter->CopyPixels(nullptr, pixels.width * 4, (UINT)pixels.bgra.size(), pixels.bgra.data()));
    return pixels;
 }
+Bytes encodePng(const Pixels &p)
+{
+    if (!p.width || !p.height || uint64_t(p.width) * p.height * 4 != p.bgra.size() ||
+        p.bgra.size() > UINT_MAX || p.width > UINT_MAX / 4)
+        throw std::runtime_error("Invalid PNG image dimensions");
+    Com<IWICImagingFactory> factory;
+    check(CoCreateInstance(CLSID_WICImagingFactory, nullptr, CLSCTX_INPROC_SERVER,
+                           IID_PPV_ARGS(factory.out())));
+    Com<IStream> stream;
+    check(CreateStreamOnHGlobal(nullptr, TRUE, stream.out()));
+    Com<IWICBitmapEncoder> encoder;
+    check(factory->CreateEncoder(GUID_ContainerFormatPng, nullptr, encoder.out()));
+    check(encoder->Initialize(stream.p, WICBitmapEncoderNoCache));
+    Com<IWICBitmapFrameEncode> frame;
+    check(encoder->CreateNewFrame(frame.out(), nullptr));
+    check(frame->Initialize(nullptr));
+    check(frame->SetSize(p.width, p.height));
+    auto format = GUID_WICPixelFormat32bppBGRA;
+    check(frame->SetPixelFormat(&format));
+    if (format != GUID_WICPixelFormat32bppBGRA)
+        throw std::runtime_error("Unsupported PNG pixel format");
+    check(frame->WritePixels(p.height, p.width * 4, (UINT)p.bgra.size(),
+                             const_cast<BYTE *>(p.bgra.data())));
+    check(frame->Commit());
+    check(encoder->Commit());
+    STATSTG stat{};
+    check(stream->Stat(&stat, STATFLAG_NONAME));
+    if (stat.cbSize.QuadPart > UINT_MAX)
+        throw std::runtime_error("PNG image is too large");
+    check(stream->Seek({}, STREAM_SEEK_SET, nullptr));
+    Bytes bytes((size_t)stat.cbSize.QuadPart);
+    ULONG read{};
+    check(stream->Read(bytes.data(), (ULONG)bytes.size(), &read));
+    if (read != bytes.size())
+        throw std::runtime_error("Cannot read encoded PNG image");
+    return bytes;
+}
 Format imageDib(const Pixels &p)
 {
    BITMAPINFOHEADER h{};
@@ -9,6 +9,7 @@ struct Pixels
 };
 Pixels decodeImage(const Clip &, UINT maxWidth = 0, UINT maxHeight = 0);
 Format imageDib(const Pixels &);
+Bytes encodePng(const Pixels &);
 std::wstring recognizeText(const Clip &);
 std::wstring recognizeText(const Clip &, const Settings &);
 std::filesystem::path tesseractExecutable(const Settings &);
@@ -13,7 +13,7 @@ class PasteProbe

  public:
    std::wstring status = L"not-requested";
-    PasteProbe(bool enabled, const std::wstring &original)
+    PasteProbe(bool enabled, HWND target)
    {
        if (!enabled)
            return;
@@ -25,6 +25,18 @@ class PasteProbe
        automation->put_TransactionTimeout(200);
        if (FAILED(automation->GetFocusedElement(&element)) || !element)
            return;
+        if (target)
+        {
+            DWORD process{};
+            GetWindowThreadProcessId(target, &process);
+            int focusedProcess{};
+            if (!process || FAILED(element->get_CurrentProcessId(&focusedProcess)) ||
+                process != static_cast<DWORD>(focusedProcess) || GetForegroundWindow() != target)
+            {
+                status = L"focused-control-changed";
+                return;
+            }
+        }
        BOOL password = TRUE;
        if (FAILED(element->get_CurrentIsPassword(&password)) || password)
        {
@@ -35,6 +47,11 @@ class PasteProbe
                                                (void **)&pattern)) ||
            !pattern)
            return;
+    }
+    PasteProbe(bool enabled, const std::wstring &original, HWND target = nullptr)
+        : PasteProbe(enabled, target)
+    {
+        if (!pattern) return;
        auto selected = read(1, false);
        auto normalize = [](std::wstring value)
        {
@@ -159,6 +159,31 @@ void showRequestedWindow(HWND window)
    if (!IsWindowVisible(window))
        ShowWindow(window, SW_SHOW);
 }
+void showMenuAccessKeys(HMENU menu)
+{
+    // Mouse-opened popups ignore the owner's keyboard-cue state.
+    // Preserve the mnemonic and expose it in the right-hand hint column.
+    for (int i = 0; i < GetMenuItemCount(menu); ++i)
+    {
+        if (auto child = GetSubMenu(menu, i)) showMenuAccessKeys(child);
+        int length = GetMenuStringW(menu, i, nullptr, 0, MF_BYPOSITION);
+        std::wstring text(length + 1, L'\0');
+        GetMenuStringW(menu, i, text.data(), (int)text.size(), MF_BYPOSITION);
+        text.resize(length);
+        if (text.find(L'\t') != text.npos) continue;
+        for (size_t p = 0; p + 1 < text.size(); ++p)
+        {
+            if (text[p] != L'&') continue;
+            if (text[p + 1] == L'&') { ++p; continue; }
+            text += L"\t" + upper(text.substr(p + 1, 1));
+            MENUITEMINFOW item{sizeof(item)};
+            item.fMask = MIIM_STRING;
+            item.dwTypeData = text.data();
+            SetMenuItemInfoW(menu, i, TRUE, &item);
+            break;
+        }
+    }
+}
 bool activateWindow(HWND window)
 {
    if (!IsWindow(window))
@@ -240,15 +265,27 @@ std::wstring processName(HWND window)
    CloseHandle(h);
    return ok ? std::filesystem::path(std::wstring(path, n)).stem().wstring() : L"";
 }
-Clip readClipboard(HWND window, size_t limit)
+Clip readClipboard(HWND window, size_t limit, ClipboardRead mode, std::optional<DWORD> expected)
 {
    ClipboardLock lock(window);
+    if (expected && *expected != GetClipboardSequenceNumber())
+        throw std::runtime_error("Clipboard changed while taking snapshot");
+    if (mode == ClipboardRead::WithoutImages &&
+        (IsClipboardFormatAvailable(CF_DIB) || IsClipboardFormatAvailable(CF_DIBV5) ||
+         IsClipboardFormatAvailable(CF_BITMAP) || IsClipboardFormatAvailable(RegisterClipboardFormatW(L"PNG"))))
+        throw std::runtime_error("Clipboard changed to an image");
    Clip c;
    size_t total = 0;
    for (UINT f = EnumClipboardFormats(0); f; f = EnumClipboardFormats(f))
    {
        if (!globalFormat(f))
            continue;
+        wchar_t name[256]{};
+        if (f >= 0xc000) GetClipboardFormatNameW(f, name, 256);
+        if (mode == ClipboardRead::Selection && f != CF_UNICODETEXT &&
+            std::wstring_view(name) != L"VisualStudioEditorOperationsLineCutCopyClipboardTag" &&
+            std::wstring_view(name) != L"MSDEVLineSelect" && std::wstring_view(name) != L"vscode-editor-data")
+            continue;
        HANDLE handle = GetClipboardData(f);
        if (!handle)
            continue;
@@ -266,8 +303,6 @@ Clip readClipboard(HWND window, size_t limit)
        GlobalUnlock(handle);
        if (f >= 0xc000)
        {
-            wchar_t name[256]{};
-            GetClipboardFormatNameW(f, name, 256);
            format.name = name;
        }
        total += size;
@@ -275,7 +310,8 @@ Clip readClipboard(HWND window, size_t limit)
    }
    return c;
 }
-DWORD writeClipboard(HWND window, const Clip &c)
+DWORD writeClipboard(HWND window, const Clip &c) { return writeClipboardGuarded(window, c, {}); }
+DWORD writeClipboardGuarded(HWND window, const Clip &c, std::optional<DWORD> expected)
 {
    // Allocate all blocks before replacing any existing data.
    std::vector<std::pair<UINT, HGLOBAL>> blocks;
@@ -302,6 +338,8 @@ DWORD writeClipboard(HWND window, const Clip &c)
            blocks.emplace_back(id, h);
        }
        ClipboardLock lock(window);
+        if (expected && *expected != GetClipboardSequenceNumber())
+            throw std::runtime_error("Clipboard changed before restoring snapshot");
        if (!EmptyClipboard())
            throw std::runtime_error("Cannot replace clipboard");
        for (auto &[id, h] : blocks)
@@ -396,22 +434,27 @@ bool chord(WORD key, UINT mods)
 bool needsSelectionDelay(HWND target)
 {
    const auto name = lower(processName(target));
-    return name == L"ms-teams" || name == L"msedgewebview2";
+    return name == L"ms-teams" || name == L"msedgewebview2" ||
+           name == L"chrome" || name == L"msedge";
 }
 bool selectPrevious(size_t count, const std::function<bool()> &valid)
 {
    if (count > 100000)
        return false;
-    // Teams' WebView editor applies selection changes asynchronously. A burst of
+    // Chromium and Teams' WebView editors apply selection changes asynchronously. A burst of
    // Shift+Left events can all use the same caret position and select only one
    // character. Give each change time to settle before sending the next one.
    const auto target = GetForegroundWindow();
+    diagnosticEvent(L"SelectPrevious requested=" + std::to_wstring(count) +
+        L" mode=" + (needsSelectionDelay(target) ? std::wstring(L"paced-25ms") : std::wstring(L"batch")));
    if (needsSelectionDelay(target))
    {
        for (size_t i = 0; i < count; ++i)
        {
            if (!valid() || GetForegroundWindow() != target || !chord(VK_LEFT, MOD_SHIFT))
                return false;
+            if (i < 32 || i + 1 == count)
+                diagnosticEvent(L"SelectPrevious Shift+Left sent=" + std::to_wstring(i + 1));
            Sleep(25);
        }
        return valid() && GetForegroundWindow() == target;
@@ -433,7 +476,10 @@ bool selectPrevious(size_t count, const std::function<bool()> &valid)
            add(VK_LEFT, KEYEVENTF_EXTENDEDKEY | KEYEVENTF_KEYUP);
        }
        add(VK_SHIFT, KEYEVENTF_KEYUP);
-        if (SendInput((UINT)inputs.size(), inputs.data(), sizeof(INPUT)) != inputs.size())
+        auto sent = SendInput((UINT)inputs.size(), inputs.data(), sizeof(INPUT));
+        diagnosticEvent(L"SelectPrevious batch offset=" + std::to_wstring(offset) + L" eventsRequested=" +
+            std::to_wstring(inputs.size()) + L" eventsSent=" + std::to_wstring(sent));
+        if (sent != inputs.size())
            return false;
    }
    return valid();
@@ -571,10 +617,25 @@ std::recursive_mutex logGate;
 bool loggingEnabled = false;
 DiagnosticBuffer diagnosticBuffer;
 }
+size_t DiagnosticBuffer::expire(ULONGLONG now)
+{
+    size_t removed = 0;
+    while (!entries.empty() && now - entries.front().first > 30000)
+    {
+        entries.pop_front();
+        ++removed;
+    }
+    return removed;
+}
+void expireDiagnostics(ULONGLONG now)
+{
+    std::lock_guard lock(logGate);
+    diagnosticBuffer.expire(now);
+}
 std::wstring DiagnosticBuffer::record(const std::wstring &message, bool problem, ULONGLONG now)
 {
-    while (!entries.empty() && (entries.size() >= 40 || now - entries.front().first > 30000))
-        entries.pop_front();
+    expire(now);
+    while (entries.size() >= 128) entries.pop_front();
    entries.emplace_back(now, message);
    if (!problem)
        return {};
@@ -38,12 +38,16 @@ HKL windowLayout(HWND);
 bool switchWindowLayout(HWND, HKL, const std::function<bool()> &valid);
 bool activateWindow(HWND);
 void showRequestedWindow(HWND);
+void showMenuAccessKeys(HMENU);
 bool ownsClipboard(HWND);
 bool webViewDescendant(DWORD owner, DWORD host,
                       const std::function<std::optional<std::pair<DWORD, std::wstring>>(DWORD)> &read);
 std::wstring processName(HWND);
-Clip readClipboard(HWND, size_t limit = 32 * 1024 * 1024);
+enum class ClipboardRead { All, Selection, WithoutImages };
+Clip readClipboard(HWND, size_t limit = 32 * 1024 * 1024,
+                   ClipboardRead = ClipboardRead::All, std::optional<DWORD> expected = {});
 DWORD writeClipboard(HWND, const Clip &);
+DWORD writeClipboardGuarded(HWND, const Clip &, std::optional<DWORD> expected);
 Clip textClip(const std::wstring &);
 bool chord(WORD key, UINT modifiers = 0);
 // Process-local marker, shared by every KSwitcher input producer (not an authentication token).
@@ -71,10 +75,12 @@ class DiagnosticBuffer
 {
    std::deque<std::pair<ULONGLONG, std::wstring>> entries;
  public:
+    size_t expire(ULONGLONG now);
    std::wstring record(const std::wstring &message, bool problem, ULONGLONG now);
    void clear() { entries.clear(); }
 };
 void setLoggingEnabled(bool enabled);
+void expireDiagnostics(ULONGLONG now);
 void diagnosticEvent(const std::wstring &message, bool problem = false);
 void diagnosticOperation(const std::string &json);
 std::wstring readDiagnosticLog(bool previous);
@@ -252,7 +252,7 @@ DWORD CALLBACK readStream(DWORD_PTR cookie, LPBYTE buffer, LONG size, LONG *read
    return 0;
 }
 } // namespace
-std::string richPreview(const Clip &clip)
+std::string richPreview(const Clip &clip, bool plainFallback)
 {
    for (const auto &f : clip.formats)
        if (f.name == L"Rich Text Format" && f.data.size() <= 65536)
@@ -276,6 +276,7 @@ std::string richPreview(const Clip &clip)
            {
            }
        }
+    if (!plainFallback) return {};
    auto text = clip.text();
    if (text.size() > 4096)
        text.resize(4096);
@@ -2,7 +2,7 @@
 #include "platform.h"
 namespace ks
 {
-std::string richPreview(const Clip &);
+std::string richPreview(const Clip &, bool plainFallback = true);
 HWND createRichText(HWND parent, int id, bool visible);
 bool setRichText(HWND, const std::string &);
 } // namespace ks
@@ -1,4 +1,5 @@
 #include "screenshot.h"
+#include "stroke_improvement.h"
 #include "ocr.h"
 #include "../resources/resource.h"
 #include <algorithm>
@@ -28,8 +29,8 @@ bool confirmScreenshotClose(HWND owner)
    dialog.hMainIcon=icon;
    dialog.dwCommonButtons=TDCBF_YES_BUTTON|TDCBF_NO_BUTTON;
    dialog.pszWindowTitle=L"KSwitcher";
-    dialog.pszMainInstruction=L"Close without copying?";
-    dialog.pszContent=L"Your latest screenshot changes have not been copied to the clipboard.";
+    dialog.pszMainInstruction=L"Close without saving or copying?";
+    dialog.pszContent=L"Your latest screenshot changes have not been saved to a file or copied to the clipboard.";
    dialog.nDefaultButton=IDNO;
    dialog.lpCallbackData=(LONG_PTR)owner;
    dialog.pfCallback=[](HWND window,UINT notification,WPARAM,LPARAM,LONG_PTR data)->HRESULT {
@@ -53,7 +54,7 @@ bool confirmScreenshotClose(HWND owner)
    // If Windows cannot display the confirmation, keep the screenshot open.
    return SUCCEEDED(result) && button==IDYES;
 }
-constexpr int ToolIds[]{27,10,11,22,23,24,25,21,19,26,20,12,18,13};
+constexpr int ToolIds[]{27,10,11,22,23,24,25,36,37,21,19,26,20,12,18,13};
 struct Surface
 {
    HDC dc = CreateCompatibleDC(nullptr);
@@ -123,7 +124,7 @@ bool chooseTextFont(HWND owner,Mark &m)
    m.fontWeight=font.lfWeight; m.fontItalic=font.lfItalic!=0;
    return true;
 }
-constexpr int CursorTools[]{10,11,22,23,24,25,19};
+constexpr int CursorTools[]{10,11,22,23,24,25,36,37,19};
 HCURSOR makeToolCursor(int tool,int size)
 {
    // Monochrome AND/XOR cursor: white outline keeps the glyph visible on dark images.
@@ -148,6 +149,8 @@ HCURSOR makeToolCursor(int tool,int size)
        case 23: Rectangle(dc,x(17),y(18),x(30),y(29)); break;
        case 24: Ellipse(dc,x(17),y(17),x(30),y(30)); break;
        case 25: Ellipse(dc,x(16),y(20),x(31),y(28)); break;
+        case 36: { POINT p[]{{x(23),y(17)},{x(31),y(30)},{x(16),y(30)},{x(23),y(17)}}; Polyline(dc,p,4); break; }
+        case 37: { POINT p[]{{x(20),y(18)},{x(27),y(18)},{x(31),y(30)},{x(16),y(30)},{x(20),y(18)}}; Polyline(dc,p,5); break; }
        case 19:
            line(18,25,25,18); line(25,18,29,22); line(29,22,22,29);
            line(22,29,18,25); line(18,25,17,30); line(17,30,22,29); break;
@@ -179,12 +182,18 @@ struct Capture
    COLORREF customColors[16]{};
    Mark stroke{};
    bool strokeConstrained{};
+    bool strokeUsedConstraint{};
    size_t strokeAnchor{};
    int strokeAxis{}; // 0 = not chosen, 1 = horizontal, 2 = vertical, 3/4 = diagonals.
    bool strokeAxisSettled{};
    std::vector<POINT> strokeMotion;
    POINT start{}, end{};
    RECT selection{}, view{};
+    RECT canvas{};
+    double zoom=1,panX=0,panY=0;
+    bool panning=false;
+    POINT panOrigin{};
+    int zoomWheelDelta=0;
    std::vector<Mark> marks;
    ScreenshotHistory history;
    HWND editor{}, inlineText{};
@@ -208,6 +217,7 @@ struct Capture
    int hoveredTool=0;
    MarkPart hoveredPart=MarkPart::None;
    std::wstring statusText;
+    std::filesystem::path savedPath;
    explicit Capture(ScreenshotHost &a) : app(a), autoOpenEditor(a.autoOpenEditor) {}
    ~Capture() {
        if(pencilCursor) DestroyCursor(pencilCursor);
@@ -239,11 +249,13 @@ void updateStatus(Capture &c)
        if(c.hoveredTool==30) text=L"Line style: solid, dotted, dashed or dash-dot";
        if(c.hoveredTool==31) text=L"Line ends: start, end, both or no arrowheads";
        if(c.hoveredTool==35) text=L"Arrow caption: F2 / double-click to edit; drag to reposition";
+        if(c.hoveredTool==28) text=L"Save (Ctrl+S) | Save As... (Ctrl+Shift+S)";
    }
    else if(c.inlineText) text=L"Text: Enter = new line | Ctrl+Enter = apply | Esc = cancel";
-    else if(part==MarkPart::Rotation) text=L"Drag to rotate text | Hold Shift for 15-degree steps";
+    else if(part==MarkPart::Rotation) text=L"Drag to rotate | Hold Shift for 15-degree steps";
    else if(part==MarkPart::Thickness) text=L"Drag to change thickness | Mouse wheel over object = size";
    else if(part==MarkPart::Radius) text=L"Drag to resize the number | Mouse wheel = diameter";
+    else if(part>=MarkPart::Vertex0 && part<=MarkPart::Vertex2) text=L"Drag triangle vertex | Other vertices stay fixed";
    else if(part==MarkPart::Start || part==MarkPart::End) text=L"Drag handle to resize | Endpoints can snap to objects and other arrows";
    else if(c.selected>=0) {
        const auto &m=c.marks[c.selected];
@@ -255,9 +267,11 @@ void updateStatus(Capture &c)
    else if(c.pointer) text=L"Pointer (V): select and edit objects | Drag handles = geometry or thickness | Empty space clears selection";
    else if(c.textTool) text=L"Text (T): click the image to type | Double-click existing text to edit";
    else if(c.highlight) text=L"Highlight (H): drag to paint | Ctrl+drag = paint over an object | V = pointer";
-    else if(c.freehand) text=L"Freehand (F): Shift = 45-degree steps; move >50 px off line to turn | Ctrl = draw over objects";
+    else if(c.freehand) text=L"Freehand (F): auto-smooth / shapes; Ctrl+Z restores original | Shift = 45-degree steps | Ctrl = draw over objects";
    else if(c.arrow) text=L"Drag to draw | Ctrl+drag over objects = linked connector | V = pointer";
    else text=L"Number (N): click to add | V = select and edit | Ctrl+C = copy screenshot";
+    text=L"Zoom: "+std::to_wstring(int(std::lround(100.0*(c.view.right-c.view.left)/c.image->width)))+
+         L"% (Ctrl +/- / wheel; Ctrl+0: fit; middle drag: pan) | "+text;
    if(text!=c.statusText) {
        c.statusText=std::move(text);
        SendMessageW(status,SB_SETTEXTW,0,(LPARAM)c.statusText.c_str());
@@ -297,6 +311,12 @@ void positionInlineText(Capture &c)
    int width=std::min(std::max(120,MulDiv(bounds.right-bounds.left,viewWidth,c.image->width)+24),std::max(32,int(client.right)-x));
    int height=std::min(std::max(40,MulDiv(bounds.bottom-bounds.top,viewWidth,c.image->width)+24),std::max(32,int(client.bottom)-c.statusHeight-y));
    SetWindowPos(c.inlineText,nullptr,x-2,y-2,width,height,SWP_NOZORDER|SWP_NOACTIVATE);
+    RECT editorBounds{x-2,y-2,x-2+width,y-2+height},visible{};
+    IntersectRect(&visible,&editorBounds,&c.canvas);
+    auto clip=IsRectEmpty(&visible)?CreateRectRgn(0,0,0,0):
+        CreateRectRgn(visible.left-editorBounds.left,visible.top-editorBounds.top,
+                      visible.right-editorBounds.left,visible.bottom-editorBounds.top);
+    if(!SetWindowRgn(c.inlineText,clip,TRUE)) DeleteObject(clip);
 }
 Mark textStyleDefaults(const Mark &source)
 {
@@ -337,6 +357,14 @@ void finishInlineText(HWND w,Capture &c,bool commit)
 }
 LRESULT CALLBACK inlineTextProc(HWND w,UINT msg,WPARAM wp,LPARAM lp,UINT_PTR,DWORD_PTR)
 {
+    if(msg==WM_KEYDOWN && (GetKeyState(VK_CONTROL)&0x8000) &&
+       (wp==VK_OEM_PLUS || wp==VK_ADD || wp==VK_OEM_MINUS || wp==VK_SUBTRACT || wp=='0' || wp==VK_NUMPAD0)) {
+        SendMessageW(GetParent(w),msg,wp,lp); return 0;
+    }
+    if(msg==WM_KEYDOWN && wp=='S' && (GetKeyState(VK_CONTROL)&0x8000)) {
+        PostMessageW(GetParent(w),WM_COMMAND,(GetKeyState(VK_SHIFT)&0x8000)?29:28,0); return 0;
+    }
+    if(msg==WM_CHAR && wp==19) return 0; // Ctrl+S is handled by the editor.
    if(msg==WM_KEYDOWN && (wp==VK_ESCAPE || (wp==VK_RETURN && (GetKeyState(VK_CONTROL)&0x8000)))) {
        PostMessageW(GetParent(w),FinishTextMessage,wp==VK_ESCAPE?2:1,(LPARAM)w); return 0;
    }
@@ -366,9 +394,47 @@ void beginMarkText(HWND w,Capture &c,int index)
        beginInlineText(w,c,label,index); c.editingLabel=true;
    }
 }
+POINT rotateShapePoint(const Mark &m,POINT p,double direction=1)
+{
+    if(m.shape==ScreenshotShape::None || m.rotation==0) return p;
+    double cx=(m.from.x+m.to.x)/2.0,cy=(m.from.y+m.to.y)/2.0;
+    double a=direction*m.rotation*3.141592653589793/180,cs=std::cos(a),sn=std::sin(a);
+    return {LONG(std::lround(cx+(p.x-cx)*cs-(p.y-cy)*sn)),
+            LONG(std::lround(cy+(p.x-cx)*sn+(p.y-cy)*cs))};
+}
+std::vector<POINT> shapeOutline(const Mark &m)
+{
+    auto points=m.points;
+    if(points.empty()) {
+        auto r=region(m.from,m.to);
+        if(m.shape==ScreenshotShape::Rectangle)
+            points={{r.left,r.top},{r.right,r.top},{r.right,r.bottom},{r.left,r.bottom},{r.left,r.top}};
+        else if(m.shape==ScreenshotShape::Triangle)
+            points={{(r.left+r.right)/2,r.top},{r.right,r.bottom},{r.left,r.bottom},{(r.left+r.right)/2,r.top}};
+        else if(m.shape==ScreenshotShape::Trapezoid)
+            points={{r.left+(r.right-r.left)/4,r.top},{r.right-(r.right-r.left)/4,r.top},
+                    {r.right,r.bottom},{r.left,r.bottom},{r.left+(r.right-r.left)/4,r.top}};
+        else {
+            for(int i=0;i<180;++i) {
+                double a=i*2*3.141592653589793/180;
+                points.push_back({LONG(std::lround((r.left+r.right)/2.0+(r.right-r.left)/2.0*std::cos(a))),
+                                  LONG(std::lround((r.top+r.bottom)/2.0+(r.bottom-r.top)/2.0*std::sin(a)))});
+            }
+            points.push_back(points.front());
+        }
+    }
+    for(auto &p:points) p=rotateShapePoint(m,p);
+    return points;
+}
 RECT markBounds(const Mark &m)
 {
    if(m.isText()) return screenshotTextBounds(m);
+    if(m.shape!=ScreenshotShape::None && m.rotation!=0) {
+        auto points=shapeOutline(m); RECT r{points[0].x,points[0].y,points[0].x,points[0].y};
+        for(auto p:points) { r.left=std::min(r.left,p.x); r.right=std::max(r.right,p.x);
+                            r.top=std::min(r.top,p.y); r.bottom=std::max(r.bottom,p.y); }
+        return r;
+    }
    RECT r=region(m.from,m.to);
    for(auto p:m.points) {
        r.left=std::min(r.left,p.x); r.top=std::min(r.top,p.y);
@@ -380,7 +446,7 @@ std::pair<POINT,POINT> thicknessSegment(const Mark &m)
 {
    if(m.shape!=ScreenshotShape::None) {
        auto r=region(m.from,m.to);
-        return {{r.right,r.top},{r.left,r.top}};
+        return {rotateShapePoint(m,{r.right,r.top}),rotateShapePoint(m,{r.left,r.top})};
    }
    if(m.freehand && m.points.size()>1) {
        size_t index=(m.points.size()-1)/2;
@@ -484,7 +550,10 @@ void drawMarks(HDC dc, const std::vector<Mark> &marks, const Mark *preview = nul
            if(m.shape!=ScreenshotShape::None) {
                auto hollow=SelectObject(dc,GetStockObject(HOLLOW_BRUSH));
                auto r=region(m.from,m.to);
-                if(m.shape==ScreenshotShape::Rectangle) Rectangle(dc,r.left,r.top,r.right+1,r.bottom+1);
+                if(!m.points.empty() || m.rotation!=0 || m.shape==ScreenshotShape::Triangle || m.shape==ScreenshotShape::Trapezoid) {
+                    auto points=shapeOutline(m); Polyline(dc,points.data(),int(points.size()));
+                }
+                else if(m.shape==ScreenshotShape::Rectangle) Rectangle(dc,r.left,r.top,r.right+1,r.bottom+1);
                else Ellipse(dc,r.left,r.top,r.right+1,r.bottom+1);
                SelectObject(dc,hollow);
                SelectObject(dc,previousPen); DeleteObject(arrowPen);
@@ -599,7 +668,7 @@ void layout(HWND w, Capture &c)
    RECT statusRect{}; GetWindowRect(status,&statusRect);
    c.statusHeight=statusRect.bottom-statusRect.top;
    r.bottom-=c.statusHeight;
-    const int positions[]{8,44,80,116,152,188,224,260,296,332,368,416,452,500};
+    const int positions[]{8,44,80,116,152,188,224,260,296,332,368,404,440,488,524,572};
    static_assert(std::size(positions)==std::size(ToolIds));
    for (size_t i = 0; i < std::size(ToolIds); ++i)
    {
@@ -607,6 +676,9 @@ void layout(HWND w, Capture &c)
        MoveWindow(GetDlgItem(w,ToolIds[i]),MulDiv(positions[i],dpi,96),MulDiv(6,dpi,96),
                   MulDiv(32,dpi,96),MulDiv(32,dpi,96),TRUE);
    }
+    SendDlgItemMessageW(w,28,WM_SETFONT,(WPARAM)c.font,TRUE);
+    MoveWindow(GetDlgItem(w,28),MulDiv(612,dpi,96),MulDiv(6,dpi,96),
+               MulDiv(78,dpi,96),MulDiv(32,dpi,96),TRUE);
    c.panelHeight=c.unit+MulDiv(40,dpi,96);
    for(int id:{30,31,32,33,34,35}) SendDlgItemMessageW(w,id,WM_SETFONT,(WPARAM)c.font,TRUE);
    MoveWindow(GetDlgItem(w,32),MulDiv(12,dpi,96),c.unit+MulDiv(6,dpi,96),MulDiv(64,dpi,96),MulDiv(24,dpi,96),TRUE);
@@ -616,13 +688,35 @@ void layout(HWND w, Capture &c)
    MoveWindow(GetDlgItem(w,34),MulDiv(480,dpi,96),c.unit+MulDiv(2,dpi,96),MulDiv(28,dpi,96),MulDiv(28,dpi,96),TRUE);
    MoveWindow(GetDlgItem(w,35),MulDiv(516,dpi,96),c.unit+MulDiv(2,dpi,96),MulDiv(28,dpi,96),MulDiv(28,dpi,96),TRUE);
    syncLineOptions(w,c);
-    double ratio = std::min({1.0, double(std::max(1L,r.right-16))/c.image->width,
+    c.canvas={0,c.panelHeight,r.right,std::max(LONG(c.panelHeight+1),r.bottom)};
+    double ratio = c.zoom*std::min({1.0, double(std::max(1L,r.right-16))/c.image->width,
                                  double(std::max(1L,r.bottom-c.panelHeight-16))/c.image->height});
-    int width = int(c.image->width*ratio), height = int(c.image->height*ratio);
-    c.view = {(r.right-width)/2, c.panelHeight+(r.bottom-c.panelHeight-height)/2,
-              (r.right+width)/2, c.panelHeight+(r.bottom-c.panelHeight+height)/2};
+    int width = std::max(1,int(std::lround(c.image->width*ratio))), height = std::max(1,int(std::lround(c.image->height*ratio)));
+    double maxX=std::max(0.0,(width-double(c.canvas.right-c.canvas.left))/2);
+    double maxY=std::max(0.0,(height-double(c.canvas.bottom-c.canvas.top))/2);
+    c.panX=std::clamp(c.panX,-maxX,maxX); c.panY=std::clamp(c.panY,-maxY,maxY);
+    LONG x=LONG(std::lround((r.right-width)/2.0+c.panX));
+    LONG y=LONG(std::lround(c.panelHeight+(r.bottom-c.panelHeight-height)/2.0+c.panY));
+    c.view = {x,y,x+width,y+height};
    InvalidateRect(w, nullptr, FALSE);
 }
+void zoomCanvas(HWND w,Capture &c,double factor,POINT anchor,bool reset=false)
+{
+    if(!c.editing || c.dragging || c.panning) return;
+    double u=double(anchor.x-c.view.left)/std::max(1L,c.view.right-c.view.left);
+    double v=double(anchor.y-c.view.top)/std::max(1L,c.view.bottom-c.view.top);
+    double next=reset?1.0:std::clamp(c.zoom*factor,.1,16.0);
+    if(next==c.zoom && !reset) return;
+    c.zoom=next;
+    if(reset) c.panX=c.panY=0;
+    layout(w,c);
+    if(!reset) {
+        c.panX+=anchor.x-(c.view.left+u*(c.view.right-c.view.left));
+        c.panY+=anchor.y-(c.view.top+v*(c.view.bottom-c.view.top));
+        layout(w,c);
+    }
+    positionInlineText(c); updateStatus(c); InvalidateRect(w,nullptr,FALSE);
+}
 POINT imagePoint(Capture &c, POINT p, bool clamp = true)
 {
    POINT result{MulDiv(p.x-c.view.left,c.image->width,std::max(1L,c.view.right-c.view.left)),
@@ -650,6 +744,10 @@ std::pair<int,MarkPart> markAt(Capture &c, POINT p)
    if(c.selected>=0)
    {
        const auto &m=c.marks[c.selected];
+        if(m.shape!=ScreenshotShape::None) {
+            auto grip=screenshotShapeRotationHandle(m,double(c.unit)*c.image->width/std::max(1L,c.view.right-c.view.left));
+            if(std::hypot(double(p.x-grip.x),double(p.y-grip.y))<=tolerance) return {c.selected,MarkPart::Rotation};
+        }
        if(m.isText() || (m.isLine() && !m.label.empty())) {
            auto text=m.isText()?m:screenshotArrowLabel(m);
            auto grip=screenshotTextRotationHandle(text,double(c.unit*0.6)*c.image->width/std::max(1L,c.view.right-c.view.left));
@@ -673,7 +771,7 @@ HCURSOR toolCursor(const Capture &c)
    if(c.pointer) return LoadCursorW(nullptr,IDC_ARROW);
    if(c.textTool) return LoadCursorW(nullptr,IDC_IBEAM);
    if(c.freehand && c.pencilCursor) return c.pencilCursor;
-    int tool=c.highlight?19:c.straight?22:c.shape!=ScreenshotShape::None?22+int(c.shape):c.arrow?11:10;
+    int tool=c.highlight?19:c.straight?22:c.shape==ScreenshotShape::Trapezoid?37:c.shape==ScreenshotShape::Triangle?36:c.shape!=ScreenshotShape::None?22+int(c.shape):c.arrow?11:10;
    for(size_t i=0;i<std::size(CursorTools);++i)
        if(CursorTools[i]==tool && c.drawingCursors[i]) return c.drawingCursors[i];
    return LoadCursorW(nullptr,IDC_CROSS);
@@ -684,12 +782,14 @@ HCURSOR actionCursor(const Capture &c,std::pair<int,MarkPart> hit,bool inside)
    LPCWSTR cursor=nullptr;
    if(hit.second==MarkPart::Body || hit.second==MarkPart::Label) cursor=IDC_SIZEALL;
    else if(hit.second==MarkPart::Rotation) cursor=IDC_HAND;
-    else if(hit.second==MarkPart::Radius) cursor=IDC_SIZEWE;
-    else if(hit.second==MarkPart::Start || hit.second==MarkPart::End || hit.second==MarkPart::Thickness) {
+    else if(hit.second>=MarkPart::Vertex0 && hit.second<=MarkPart::Vertex2) cursor=IDC_SIZEALL;
+    else if(hit.second==MarkPart::Start || hit.second==MarkPart::End || hit.second==MarkPart::Radius)
+        cursor=IDC_SIZEALL;
+    else if(hit.second==MarkPart::Thickness) {
        const auto &mark=c.marks[hit.first];
-        auto [from,to]=hit.second==MarkPart::Thickness?thicknessSegment(mark):std::pair{mark.from,mark.to};
+        auto [from,to]=thicknessSegment(mark);
        double angle=std::atan2(double(to.y-from.y),double(to.x-from.x));
-        if(hit.second==MarkPart::Thickness) angle+=3.141592653589793/2;
+        angle+=3.141592653589793/2;
        int axis=(int(std::lround(angle/(3.141592653589793/4)))+8)%4;
        const LPCWSTR cursors[]{IDC_SIZEWE,IDC_SIZENWSE,IDC_SIZENS,IDC_SIZENESW};
        cursor=cursors[axis];
@@ -699,7 +799,7 @@ HCURSOR actionCursor(const Capture &c,std::pair<int,MarkPart> hit,bool inside)
 void captureCursor(HWND w, Capture &c)
 {
    POINT p; GetCursorPos(&p); ScreenToClient(w,&p);
-    bool inside=PtInRect(&c.view,p)!=FALSE;
+    bool inside=PtInRect(&c.view,p) && PtInRect(&c.canvas,p);
    auto hit=c.editing?(c.dragging?std::pair{c.selected,c.part}:markAt(c,imagePoint(c,p,false))):std::pair{-1,MarkPart::None};
    if(!c.dragging && !inside && hit.second!=MarkPart::Thickness && hit.second!=MarkPart::Rotation) hit={-1,MarkPart::None};
    SetCursor(actionCursor(c,hit,inside || c.dragging));
@@ -755,7 +855,18 @@ void drawHandles(HDC dc, const Capture &c)
        handle({m.from.x+m.radius,m.from.y});
    }
    else {
-        handle(m.from); handle(m.to);
+        if(m.shape==ScreenshotShape::Triangle) {
+            auto vertices=shapeOutline(m);
+            for(size_t i=0;i<3;++i) handle(vertices[i]);
+        } else { handle(rotateShapePoint(m,m.from)); handle(rotateShapePoint(m,m.to)); }
+        if(m.shape!=ScreenshotShape::None) {
+            auto r=region(m.from,m.to);
+            auto top=point(rotateShapePoint(m,{(r.left+r.right)/2,r.top}));
+            auto grip=screenshotShapeRotationHandle(m,double(c.unit)*c.image->width/std::max(1L,c.view.right-c.view.left));
+            auto end=point(grip); MoveToEx(dc,top.x,top.y,nullptr); LineTo(dc,end.x,end.y);
+            int radius=std::max(4,c.unit/8);
+            Ellipse(dc,end.x-radius,end.y-radius,end.x+radius+1,end.y+radius+1);
+        }
        auto [from,to]=thicknessSegment(m);
        auto mid=point({(from.x+to.x)/2,(from.y+to.y)/2});
        auto grip=thicknessHandle(c,m),end=point(grip);
@@ -771,7 +882,8 @@ void drawTool(const DRAWITEMSTRUCT &item, const Capture &c)
    RECT r=item.rcItem;
    bool active=(item.CtlID==27 && c.pointer)||(item.CtlID==10 && !c.pointer && !c.arrow && !c.highlight && !c.freehand && !c.textTool)||(item.CtlID==11 && c.arrow && !c.straight && c.shape==ScreenshotShape::None)||
                (item.CtlID==19 && c.highlight)||(item.CtlID==21 && c.freehand)||
-                (item.CtlID==22 && c.straight)||(item.CtlID>=23 && item.CtlID<=25 && int(c.shape)==int(item.CtlID)-22)||(item.CtlID==26 && c.textTool);
+                (item.CtlID==22 && c.straight)||(item.CtlID>=23 && item.CtlID<=25 && int(c.shape)==int(item.CtlID)-22)||(item.CtlID==26 && c.textTool)||
+                (item.CtlID==36 && c.shape==ScreenshotShape::Triangle)||(item.CtlID==37 && c.shape==ScreenshotShape::Trapezoid);
    bool disabled=item.itemState&ODS_DISABLED;
    POINT mouse; GetCursorPos(&mouse); ScreenToClient(item.hwndItem,&mouse);
    bool hover=PtInRect(&r,mouse) && !disabled;
@@ -785,7 +897,16 @@ void drawTool(const DRAWITEMSTRUCT &item, const Capture &c)
    RoundRect(dc,r.left,r.top,r.right,r.bottom,corner,corner);
    SelectObject(dc,oldPen); SelectObject(dc,oldBrush); DeleteObject(pen); DeleteObject(brush);
    int iconIndex=item.CtlID==35?13:item.CtlID==34?14:item.CtlID>=22?int(item.CtlID)-13:item.CtlID==18?5:item.CtlID==19?6:item.CtlID==20?7:item.CtlID==21?8:item.CtlID-10;
-    auto icon=item.CtlID==27?(HICON)LoadCursorW(nullptr,IDC_ARROW):c.toolIcons[disabled?2:active?1:0][iconIndex];
+    auto icon=(item.CtlID==36 || item.CtlID==37)?nullptr:item.CtlID==27?(HICON)LoadCursorW(nullptr,IDC_ARROW):c.toolIcons[disabled?2:active?1:0][iconIndex];
+    if(item.CtlID==36 || item.CtlID==37) {
+        int cx=(r.left+r.right)/2,cy=(r.top+r.bottom)/2,s=c.iconSize/2;
+        auto trianglePen=CreatePen(PS_SOLID,std::max(1,MulDiv(2,GetDpiForWindow(item.hwndItem),96)),
+                                  disabled?RGB(148,163,184):active?RGB(37,99,235):RGB(51,65,85));
+        auto previous=SelectObject(dc,trianglePen);
+        if(item.CtlID==36) { POINT vertices[]{{cx,cy-s},{cx+s,cy+s},{cx-s,cy+s},{cx,cy-s}}; Polyline(dc,vertices,4); }
+        else { POINT vertices[]{{cx-s/2,cy-s},{cx+s/2,cy-s},{cx+s,cy+s},{cx-s,cy+s},{cx-s/2,cy-s}}; Polyline(dc,vertices,5); }
+        SelectObject(dc,previous); DeleteObject(trianglePen);
+    }
    if(icon) DrawIconEx(dc,(r.right-c.iconSize)/2,(r.bottom-c.iconSize)/2,icon,c.iconSize,c.iconSize,0,nullptr,DI_NORMAL);
    if(item.CtlID==20) {
        auto color=c.selected>=0?c.marks[c.selected].color:c.currentColor;
@@ -821,6 +942,64 @@ void copy(HWND w, Capture &c, DWORD (*publish)(HWND,const Clip &)=writeClipboard
    publish(c.app.window, clip);
    c.copied=true;
 }
+void saveToFile(HWND w, Capture &c, const std::filesystem::path &path)
+{
+    finishInlineText(w,c,true);
+    auto pixels=decodeImage(screenshotClip(c.image->dc,c.image->width,c.image->height,c.marks));
+    // GDI-rendered screenshot pixels are opaque; GDI does not maintain alpha.
+    for(size_t i=3;i<pixels.bgra.size();i+=4) pixels.bgra[i]=255;
+    auto bytes=encodePng(pixels);
+    GUID id{};
+    if(FAILED(CoCreateGuid(&id))) throw std::runtime_error("Cannot prepare screenshot output file");
+    wchar_t unique[40]{}; StringFromGUID2(id,unique,(int)std::size(unique));
+    auto temporary=path.parent_path()/(L".kswitcher-"+std::wstring(unique)+L".png");
+    try {
+        atomicWrite(temporary,bytes);
+        if(!MoveFileExW(temporary.c_str(),path.c_str(),MOVEFILE_REPLACE_EXISTING|MOVEFILE_WRITE_THROUGH))
+            throw std::runtime_error("Cannot save screenshot to the selected file");
+    } catch(...) {
+        std::error_code ignored; std::filesystem::remove(temporary,ignored); throw;
+    }
+    c.savedPath=path;
+    c.copied=true; // Current edits have been exported, either to file or clipboard.
+}
+void save(HWND w, Capture &c, bool saveAs=false,
+          BOOL (WINAPI *chooseFile)(LPOPENFILENAMEW)=GetSaveFileNameW)
+{
+    if(!saveAs && !c.savedPath.empty()) {
+        saveToFile(w,c,c.savedPath);
+        return;
+    }
+    wchar_t filename[32768]{};
+    auto proposed=c.savedPath.wstring();
+    if(proposed.empty()) {
+        SYSTEMTIME time{}; GetLocalTime(&time);
+        wchar_t name[100]{};
+        swprintf_s(name,L"Screenshot-%04u%02u%02u-%02u%02u%02u.png",
+                   time.wYear,time.wMonth,time.wDay,time.wHour,time.wMinute,time.wSecond);
+        proposed=name;
+    }
+    if(proposed.size()>=std::size(filename)) throw std::runtime_error("Screenshot file path is too long");
+    std::copy(proposed.begin(),proposed.end(),filename);
+    OPENFILENAMEW dialog{sizeof(dialog)};
+    dialog.hwndOwner=w;
+    dialog.lpstrTitle=L"Save screenshot";
+    dialog.lpstrFilter=L"PNG image (*.png)\0*.png\0\0";
+    dialog.nFilterIndex=1;
+    dialog.lpstrFile=filename;
+    dialog.nMaxFile=(DWORD)std::size(filename);
+    dialog.lpstrDefExt=L"png";
+    dialog.Flags=OFN_OVERWRITEPROMPT|OFN_PATHMUSTEXIST|OFN_NOCHANGEDIR|OFN_EXPLORER;
+    if(!chooseFile(&dialog)) {
+        if(CommDlgExtendedError()) throw std::runtime_error("Cannot open the screenshot save dialog");
+        return;
+    }
+    if(lower(std::filesystem::path(filename).extension().wstring())!=L".png")
+        throw std::runtime_error("Choose a filename ending in .png for the screenshot");
+    saveToFile(w,c,filename);
+    c.statusText=L"Saved: "+c.savedPath.wstring();
+    SendDlgItemMessageW(w,50,SB_SETTEXTW,0,(LPARAM)c.statusText.c_str());
+}
 void edit(HWND w, Capture &c)
 {
    auto r = region(c.start,c.end);
@@ -846,9 +1025,12 @@ void edit(HWND w, Capture &c)
    InitCommonControlsEx(&statusControls);
    CreateWindowExW(0,STATUSCLASSNAMEW,L"",WS_CHILD|WS_VISIBLE|SBARS_TOOLTIPS,
        0,0,0,0,w,(HMENU)50,c.app.instance,nullptr);
-    const wchar_t *labels[]{L"Pointer (V): select and edit objects", L"Number (N)", L"Arrow (A); Ctrl+drag between objects to link", L"Straight line (L); Ctrl+drag between objects to link", L"Rectangle (R)", L"Circle (O)", L"Ellipse (E)", L"Freehand line (F); Shift for 45-degree steps; move >50 px off line to turn; Ctrl to draw over objects", L"Highlight (H); Ctrl+drag to paint over an object",
+    const wchar_t *labels[]{L"Pointer (V): select and edit objects", L"Number (N)", L"Arrow (A); Ctrl+drag between objects to link", L"Straight line (L); Ctrl+drag between objects to link", L"Rectangle (R)", L"Circle (O)", L"Ellipse (E)", L"Triangle (G): drag to draw; drag each vertex to reshape", L"Trapezoid (B): drag to draw", L"Freehand line (F); Shift for 45-degree steps; move >50 px off line to turn; Ctrl to draw over objects", L"Highlight (H); Ctrl+drag to paint over an object",
        L"Text (T); double-click or F2 to edit", L"Color — selected object and new objects", L"Undo (Ctrl+Z)", L"Redo (Ctrl+Y / Ctrl+Shift+Z)", L"Copy (Ctrl+C)"};
    static_assert(std::size(labels)==std::size(ToolIds));
+    auto saveButton=CreateWindowW(L"BUTTON",L"Save...",WS_CHILD|WS_VISIBLE|WS_TABSTOP|BS_PUSHBUTTON,
+        0,0,0,0,w,(HMENU)28,c.app.instance,nullptr);
+    SetWindowSubclass(saveButton,toolHover,1,0);
    auto tips=CreateWindowExW(WS_EX_TOPMOST,TOOLTIPS_CLASSW,nullptr,WS_POPUP|TTS_ALWAYSTIP|TTS_NOPREFIX,
                             CW_USEDEFAULT,CW_USEDEFAULT,CW_USEDEFAULT,CW_USEDEFAULT,w,nullptr,c.app.instance,nullptr);
    for (size_t i=0;i<std::size(ToolIds);++i)
@@ -938,7 +1120,7 @@ LRESULT CALLBACK captureProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
            }
            break;
        case WM_DRAWITEM:
-            if((wp>=10 && wp<=13) || (wp>=18 && wp<=27) || wp==34 || wp==35) { drawTool(*reinterpret_cast<DRAWITEMSTRUCT *>(lp),*c); return TRUE; }
+            if((wp>=10 && wp<=13) || (wp>=18 && wp<=27) || wp==34 || wp==35 || wp==36 || wp==37) { drawTool(*reinterpret_cast<DRAWITEMSTRUCT *>(lp),*c); return TRUE; }
            break;
        case WM_CTLCOLORSTATIC:
            SetBkColor((HDC)wp,RGB(255,255,255)); SetTextColor((HDC)wp,RGB(51,65,85));
@@ -1023,19 +1205,22 @@ LRESULT CALLBACK captureProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
                if(next!=value) { c->remember(c->marks); value=next; resolveScreenshotLinks(c->marks); }
            }
            if (LOWORD(wp)==13) { copy(w,*c); return 0; }
+            if (LOWORD(wp)==28 || LOWORD(wp)==29) {
+                save(w,*c,LOWORD(wp)==29); SetFocus(w); return 0;
+            }
            if (LOWORD(wp)==12 || LOWORD(wp)==18)
            {
                bool changed=LOWORD(wp)==12?c->history.undo(c->marks):c->history.redo(c->marks);
                if(changed) { c->copied=false; c->selected=-1; c->selectedLabel=false; c->wheelDelta=0; c->wheelTarget=-1; }
                c->syncHistory();
            }
-            if (LOWORD(wp)==10 || LOWORD(wp)==11 || LOWORD(wp)==19 || (LOWORD(wp)>=21 && LOWORD(wp)<=27))
+            if (LOWORD(wp)==10 || LOWORD(wp)==11 || LOWORD(wp)==19 || LOWORD(wp)==36 || LOWORD(wp)==37 || (LOWORD(wp)>=21 && LOWORD(wp)<=27))
            {
                c->pointer=LOWORD(wp)==27;
-                c->arrow = LOWORD(wp)==11 || (LOWORD(wp)>=22 && LOWORD(wp)<=25);
+                c->arrow = LOWORD(wp)==11 || LOWORD(wp)==36 || LOWORD(wp)==37 || (LOWORD(wp)>=22 && LOWORD(wp)<=25);
                c->straight=LOWORD(wp)==22;
                c->textTool=LOWORD(wp)==26;
-                c->shape=LOWORD(wp)>=23 && LOWORD(wp)<=25?ScreenshotShape(LOWORD(wp)-22):ScreenshotShape::None;
+                c->shape=LOWORD(wp)==37?ScreenshotShape::Trapezoid:LOWORD(wp)==36?ScreenshotShape::Triangle:LOWORD(wp)>=23 && LOWORD(wp)<=25?ScreenshotShape(LOWORD(wp)-22):ScreenshotShape::None;
                c->selected=-1; c->selectedLabel=false;
                c->highlight=LOWORD(wp)==19;
                c->freehand=LOWORD(wp)==21;
@@ -1046,12 +1231,15 @@ LRESULT CALLBACK captureProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
                InvalidateRect(GetDlgItem(w,19),nullptr,FALSE);
                InvalidateRect(GetDlgItem(w,21),nullptr,FALSE);
                for(int id=22;id<=27;++id) InvalidateRect(GetDlgItem(w,id),nullptr,FALSE);
+                InvalidateRect(GetDlgItem(w,36),nullptr,FALSE);
+                InvalidateRect(GetDlgItem(w,37),nullptr,FALSE);
            }

            SetFocus(w); captureCursor(w,*c); InvalidateRect(w,nullptr,FALSE); return 0;
        case WM_KEYDOWN:
            if(wp==VK_SHIFT && c->editing && c->dragging && c->freehand && c->part==MarkPart::None && !c->strokeConstrained) {
                c->strokeConstrained=true;
+                c->strokeUsedConstraint=true;
                c->strokeAnchor=c->stroke.points.size()-1;
                c->strokeAxis=0;
                c->strokeAxisSettled=false;
@@ -1063,6 +1251,12 @@ LRESULT CALLBACK captureProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
            }
            if (c->editing && !c->dragging)
            {
+                if((GetKeyState(VK_CONTROL)&0x8000) &&
+                   (wp==VK_OEM_PLUS || wp==VK_ADD || wp==VK_OEM_MINUS || wp==VK_SUBTRACT || wp=='0' || wp==VK_NUMPAD0)) {
+                    POINT center{(c->canvas.left+c->canvas.right)/2,(c->canvas.top+c->canvas.bottom)/2};
+                    zoomCanvas(w,*c,wp==VK_OEM_MINUS || wp==VK_SUBTRACT?1/1.25:1.25,center,wp=='0' || wp==VK_NUMPAD0);
+                    return 0;
+                }
                if(wp>=VK_LEFT && wp<=VK_DOWN && c->selected>=0 && !c->inlineText) {
                    POINT delta{wp==VK_LEFT?-1L:wp==VK_RIGHT?1L:0L,wp==VK_UP?-1L:wp==VK_DOWN?1L:0L};
                    const auto &original=c->marks[c->selected];
@@ -1079,6 +1273,9 @@ LRESULT CALLBACK captureProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
                    beginMarkText(w,*c,c->selected); return 0;
                }
                if ((GetKeyState(VK_CONTROL)&0x8000) && wp=='C') { copy(w,*c); return 0; }
+                if ((GetKeyState(VK_CONTROL)&0x8000) && wp=='S') {
+                    save(w,*c,(GetKeyState(VK_SHIFT)&0x8000)!=0); SetFocus(w); return 0;
+                }
                if ((GetKeyState(VK_CONTROL)&0x8000) && (wp=='Z' || wp=='Y'))
                    SendMessageW(w,WM_COMMAND,wp=='Y'||(GetKeyState(VK_SHIFT)&0x8000)?18:12,0);
                if ((GetKeyState(VK_CONTROL)&0x8000) && wp=='D' && c->selected>=0)
@@ -1094,6 +1291,8 @@ LRESULT CALLBACK captureProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
                    if(wp=='R') SendMessageW(w,WM_COMMAND,23,0);
                    if(wp=='O') SendMessageW(w,WM_COMMAND,24,0);
                    if(wp=='E') SendMessageW(w,WM_COMMAND,25,0);
+                    if(wp=='G') SendMessageW(w,WM_COMMAND,36,0);
+                    if(wp=='B') SendMessageW(w,WM_COMMAND,37,0);
                }
                if (wp=='N' || wp=='A') SendMessageW(w,WM_COMMAND,wp=='N'?10:11,0);
                if(wp=='H') SendMessageW(w,WM_COMMAND,19,0);
@@ -1118,7 +1317,7 @@ LRESULT CALLBACK captureProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
        case WM_LBUTTONDBLCLK:
            if(c->editing && !c->dragging) {
                POINT p{GET_X_LPARAM(lp),GET_Y_LPARAM(lp)};
-                if(PtInRect(&c->view,p)) {
+                if(PtInRect(&c->view,p) && PtInRect(&c->canvas,p)) {
                    auto [index,part]=markAt(*c,imagePoint(*c,p));
                    if(index>=0 && (c->marks[index].isText() || c->marks[index].isLine())) {
                        c->selected=index; beginMarkText(w,*c,index);
@@ -1128,8 +1327,10 @@ LRESULT CALLBACK captureProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
            return 0;
        case WM_LBUTTONDOWN:
        {
+            if(c->panning) return 0;
            finishInlineText(w,*c,true);
            POINT p{GET_X_LPARAM(lp),GET_Y_LPARAM(lp)};
+            if(c->editing && !PtInRect(&c->canvas,p)) return 0;
            auto hitPart=c->editing?markAt(*c,imagePoint(*c,p,false)).second:MarkPart::None;
            bool thickness=hitPart==MarkPart::Thickness || hitPart==MarkPart::Rotation;
            if (c->editing && !PtInRect(&c->view,p) && !thickness)
@@ -1172,6 +1373,7 @@ LRESULT CALLBACK captureProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
                    c->stroke.freehand=c->freehand; c->stroke.style=c->lineStyle; c->stroke.ends=c->freehandEnds;
                    c->stroke.points.push_back(p);
                    c->strokeConstrained=false;
+                    c->strokeUsedConstraint=(wp&MK_SHIFT)!=0;
                }
                c->dragging=true; SetCapture(w);
            }
@@ -1179,8 +1381,17 @@ LRESULT CALLBACK captureProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
        }
        case WM_MOUSEWHEEL:
        {
-            if(!c->editing || c->dragging) return 0;
+            if(!c->editing || c->dragging || c->panning) return 0;
            POINT p{GET_X_LPARAM(lp),GET_Y_LPARAM(lp)}; ScreenToClient(w,&p);
+            if(!PtInRect(&c->canvas,p)) return 0;
+            if(GET_KEYSTATE_WPARAM(wp)&MK_CONTROL) {
+                c->wheelDelta=0; c->wheelTarget=-1;
+                c->zoomWheelDelta+=GET_WHEEL_DELTA_WPARAM(wp);
+                int steps=c->zoomWheelDelta/WHEEL_DELTA; c->zoomWheelDelta%=WHEEL_DELTA;
+                if(steps) zoomCanvas(w,*c,std::pow(1.25,steps),p);
+                return 0;
+            }
+            c->zoomWheelDelta=0;
            if(!PtInRect(&c->view,p)) return 0;
            auto [index,part]=markAt(*c,imagePoint(*c,p));
            if(index<0) { c->wheelDelta=0; c->wheelTarget=-1; return 0; }
@@ -1200,8 +1411,27 @@ LRESULT CALLBACK captureProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
            }
            return 0;
        }
+        case WM_MBUTTONDOWN:
+        {
+            POINT p{GET_X_LPARAM(lp),GET_Y_LPARAM(lp)};
+            if(c->editing && !c->dragging && PtInRect(&c->canvas,p)) {
+                c->panning=true; c->panOrigin=p; SetCapture(w); SetCursor(LoadCursorW(nullptr,IDC_SIZEALL));
+            }
+            return 0;
+        }
+        case WM_MBUTTONUP:
+            if(c->panning) { c->panning=false; ReleaseCapture(); captureCursor(w,*c); }
+            return 0;
        case WM_MOUSEMOVE:
        case WM_LBUTTONUP:
+            if(c->panning) {
+                if(msg==WM_MOUSEMOVE) {
+                    POINT p{GET_X_LPARAM(lp),GET_Y_LPARAM(lp)};
+                    c->panX+=p.x-c->panOrigin.x; c->panY+=p.y-c->panOrigin.y; c->panOrigin=p;
+                    layout(w,*c); positionInlineText(*c); SetCursor(LoadCursorW(nullptr,IDC_SIZEALL));
+                }
+                return 0;
+            }
            if (c->dragging)
            {
                POINT p{GET_X_LPARAM(lp),GET_Y_LPARAM(lp)};
@@ -1210,6 +1440,7 @@ LRESULT CALLBACK captureProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
                    c->end=constrainScreenshotShape(c->shape,c->start,c->end,c->image->width,c->image->height);
                if(c->editing && (c->highlight || c->freehand) && c->part==MarkPart::None) {
                    bool constrained=c->freehand && ((wp&MK_SHIFT) || (GetKeyState(VK_SHIFT)&0x8000));
+                    c->strokeUsedConstraint=c->strokeUsedConstraint || constrained;
                    if(constrained) {
                        if(!c->strokeConstrained) {
                            c->strokeAnchor=c->stroke.points.size()-1;
@@ -1303,6 +1534,25 @@ LRESULT CALLBACK captureProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
                            linkScreenshotEndpoint(mark,false,c->end,c->marks,6);
                            resolveScreenshotLinks(c->marks);
                        }
+                        if(c->freehand && !c->strokeUsedConstraint &&
+                           !c->marks.back().fromNumber && !c->marks.back().toNumber &&
+                           !c->marks.back().fromLink.target && !c->marks.back().toLink.target) {
+                            ScreenshotShape recognized{};
+                            bool straightLine=false;
+                            auto improved=improveScreenshotStroke(c->marks.back().points,&recognized,&straightLine);
+                            if(!improved.empty()) {
+                                c->remember(c->marks);
+                                auto &mark=c->marks.back();
+                                mark.points=std::move(improved);
+                                mark.from=mark.points.front(); mark.to=mark.points.back();
+                                if(straightLine) { mark.points.clear(); mark.freehand=false; }
+                                if(recognized!=ScreenshotShape::None) {
+                                    mark.shape=recognized; mark.freehand=false; mark.ends=LineEnds::None;
+                                    auto bounds=markBounds(mark);
+                                    mark.from={bounds.left,bounds.top}; mark.to={bounds.right,bounds.bottom};
+                                }
+                            }
+                        }
                        c->selected=int(c->marks.size())-1; c->selectedLabel=false;
                    }
                    else if (std::hypot(double(c->end.x-c->start.x),double(c->end.y-c->start.y))>=4)
@@ -1313,6 +1563,7 @@ LRESULT CALLBACK captureProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
                        c->marks.back().style=c->lineStyle; c->marks.back().ends=c->straight || c->shape!=ScreenshotShape::None?LineEnds::None:c->arrowEnds;
                        c->marks.back().shape=c->shape;
                        auto &mark=c->marks.back();
+                        if(mark.shape==ScreenshotShape::Triangle || mark.shape==ScreenshotShape::Trapezoid) mark.points=shapeOutline(mark);
                        linkScreenshotEndpoint(mark,true,c->start,c->marks,6);
                        linkScreenshotEndpoint(mark,false,c->end,c->marks,6);
                        resolveScreenshotLinks(c->marks);
@@ -1325,6 +1576,7 @@ LRESULT CALLBACK captureProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
            captureCursor(w,*c);
            return 0;
        case WM_CAPTURECHANGED:
+            c->panning=false;
            if(c->dragging && c->part!=MarkPart::None)
            {
                c->marks=std::move(c->beforeDrag); c->part=MarkPart::None;
@@ -1334,7 +1586,7 @@ LRESULT CALLBACK captureProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
            if (c->editing)
            {
                auto limits = reinterpret_cast<MINMAXINFO *>(lp);
-                limits->ptMinTrackSize = {MulDiv(650,GetDpiForWindow(w),96),MulDiv(240,GetDpiForWindow(w),96)};
+                limits->ptMinTrackSize = {MulDiv(730,GetDpiForWindow(w),96),MulDiv(240,GetDpiForWindow(w),96)};
                return 0;
            }
            break;
@@ -1384,7 +1636,7 @@ LRESULT CALLBACK captureProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
                    auto previous=SelectObject(buffer,divider);
                    MoveToEx(buffer,0,c->panelHeight-1,nullptr); LineTo(buffer,client.right,c->panelHeight-1);
                    int dpi=GetDpiForWindow(w);
-                    for(int x:{368,452}) {
+                    for(int x:{440,524}) {
                        MoveToEx(buffer,MulDiv(x,dpi,96),MulDiv(13,dpi,96),nullptr);
                        LineTo(buffer,MulDiv(x,dpi,96),MulDiv(31,dpi,96));
                    }
@@ -1402,9 +1654,12 @@ LRESULT CALLBACK captureProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
                    }
                    drawMarks(rendered.dc,visibleMarks,c->dragging && c->part==MarkPart::None?((c->highlight || c->freehand)?&c->stroke:&preview):nullptr);
                    SetStretchBltMode(buffer,HALFTONE); SetBrushOrgEx(buffer,0,0,nullptr);
+                    int savedCanvas=SaveDC(buffer);
+                    IntersectClipRect(buffer,c->canvas.left,c->canvas.top,c->canvas.right,c->canvas.bottom);
                    StretchBlt(buffer,c->view.left,c->view.top,c->view.right-c->view.left,c->view.bottom-c->view.top,
                               rendered.dc,0,0,rendered.width,rendered.height,SRCCOPY);
                    drawHandles(buffer,*c);
+                    RestoreDC(buffer,savedCanvas);
                    BitBlt(dc,0,0,width,height,buffer,0,0,SRCCOPY);
                }
            }
@@ -1449,6 +1704,11 @@ POINT screenshotTextRotationHandle(const ScreenshotMark &m,double clearance)
    auto r=plainTextBounds(m);
    return rotateTextPoint(m,{(r.left+r.right)/2,r.top-LONG(std::lround(clearance))});
 }
+POINT screenshotShapeRotationHandle(const ScreenshotMark &m,double clearance)
+{
+    auto r=region(m.from,m.to);
+    return rotateShapePoint(m,{(r.left+r.right)/2,r.top-LONG(std::lround(clearance))});
+}
 ScreenshotMark screenshotArrowLabel(const ScreenshotMark &m)
 {
    ScreenshotMark label{{0,0},{0,0},0};
@@ -1528,23 +1788,23 @@ void assignMarkIds(std::vector<ScreenshotMark> &marks)
 }
 POINT objectAnchor(const ScreenshotMark &m,const ScreenshotLink &link)
 {
-    if(m.isText() || m.shape!=ScreenshotShape::None) {
+    if(m.isText() || (m.shape!=ScreenshotShape::None && m.points.empty())) {
        auto r=m.isText()?plainTextBounds(m):region(m.from,m.to);
        POINT p{LONG(std::lround(r.left+(r.right-r.left)*link.u)),LONG(std::lround(r.top+(r.bottom-r.top)*link.v))};
-        return m.isText()?rotateTextPoint(m,p):p;
+        return m.isText()?rotateTextPoint(m,p):rotateShapePoint(m,p);
    }
    size_t segments=m.points.size()>1?m.points.size()-1:1;
    double along=std::clamp(link.u,0.0,1.0)*segments;
    size_t i=std::min(size_t(along),segments-1); double t=along-i;
    POINT a=m.points.size()>1?m.points[i]:m.from,b=m.points.size()>1?m.points[i+1]:m.to;
-    return {LONG(std::lround(a.x+(b.x-a.x)*t)),LONG(std::lround(a.y+(b.y-a.y)*t))};
+    return rotateShapePoint(m,{LONG(std::lround(a.x+(b.x-a.x)*t)),LONG(std::lround(a.y+(b.y-a.y)*t))});
 }
 bool findObjectAnchor(const ScreenshotMark &m,POINT drop,double tolerance,ScreenshotLink &link)
 {
    link={m.id,0,0};
-    if(m.isText() || m.shape!=ScreenshotShape::None) {
+    if(m.isText() || (m.shape!=ScreenshotShape::None && m.points.empty())) {
        auto r=m.isText()?plainTextBounds(m):region(m.from,m.to);
-        POINT p=m.isText()?rotateTextPoint(m,drop,-1):drop;
+        POINT p=m.isText()?rotateTextPoint(m,drop,-1):rotateShapePoint(m,drop,-1);
        double w=std::max(1L,r.right-r.left),h=std::max(1L,r.bottom-r.top);
        double x=(p.x-r.left)/w,y=(p.y-r.top)/h;
        bool inside=x>=0 && x<=1 && y>=0 && y<=1;
@@ -1564,6 +1824,7 @@ bool findObjectAnchor(const ScreenshotMark &m,POINT drop,double tolerance,Screen
        auto anchor=objectAnchor(m,link);
        return inside || std::hypot(double(drop.x-anchor.x),double(drop.y-anchor.y))<=tolerance;
    }
+    drop=rotateShapePoint(m,drop,-1);
    double best=1e100;
    size_t segments=m.points.size()>1?m.points.size()-1:1;
    for(size_t i=0;i<segments;++i) {
@@ -1648,6 +1909,13 @@ void resolveScreenshotLinks(std::vector<ScreenshotMark> &marks)
 }
 MarkPart hitScreenshotMark(const ScreenshotMark &m, POINT p, double tolerance)
 {
+    if(m.shape==ScreenshotShape::Triangle) {
+        auto vertices=shapeOutline(m);
+        for(int i=0;i<3;++i)
+            if(std::hypot(double(p.x-vertices[i].x),double(p.y-vertices[i].y))<=tolerance)
+                return MarkPart(int(MarkPart::Vertex0)+i);
+    }
+    p=rotateShapePoint(m,p,-1);
    if(m.isText()) {
        auto r=plainTextBounds(m);
        auto local=rotateTextPoint(m,p,-1);
@@ -1658,8 +1926,10 @@ MarkPart hitScreenshotMark(const ScreenshotMark &m, POINT p, double tolerance)
    auto distance=[](POINT a, POINT b) { return std::hypot(double(a.x-b.x),double(a.y-b.y)); };
    if(!m.points.empty())
    {
-        if(m.freehand && distance(p,m.from)<=tolerance) return MarkPart::Start;
-        if(m.freehand && distance(p,m.to)<=tolerance) return MarkPart::End;
+        if(m.shape!=ScreenshotShape::Triangle) {
+            if((m.freehand || m.shape!=ScreenshotShape::None) && distance(p,m.from)<=tolerance) return MarkPart::Start;
+            if((m.freehand || m.shape!=ScreenshotShape::None) && distance(p,m.to)<=tolerance) return MarkPart::End;
+        }
        double reach=tolerance+std::clamp(m.thickness,m.isHighlight()?4:1,m.isHighlight()?100:30)/2.0;
        POINT from=m.points.front();
        for(auto to:m.points) {
@@ -1713,7 +1983,32 @@ ScreenshotMark dragScreenshotMark(const ScreenshotMark &original, MarkPart part,
 {
    auto m=original;
    if(position.x==origin.x && position.y==origin.y) return m;
-    if(part==MarkPart::Rotation && (m.isText() || (m.isLine() && !m.label.empty()))) {
+    if(part>=MarkPart::Vertex0 && part<=MarkPart::Vertex2 && m.shape==ScreenshotShape::Triangle) {
+        if(m.points.empty()) { auto local=m; local.rotation=0; m.points=shapeOutline(local); }
+        size_t index=size_t(int(part)-int(MarkPart::Vertex0)),fixed=(index+1)%3;
+        auto fixedWorld=rotateShapePoint(m,m.points[fixed]);
+        auto vertexWorld=rotateShapePoint(m,m.points[index]);
+        POINT target{std::clamp(vertexWorld.x+position.x-origin.x,0L,LONG(width-1)),
+                     std::clamp(vertexWorld.y+position.y-origin.y,0L,LONG(height-1))};
+        m.points[index]=rotateShapePoint(m,target,-1); m.points[3]=m.points[0];
+        RECT bounds{m.points[0].x,m.points[0].y,m.points[0].x,m.points[0].y};
+        for(size_t i=1;i<3;++i) {auto p=m.points[i]; bounds.left=std::min(bounds.left,p.x); bounds.right=std::max(bounds.right,p.x);
+            bounds.top=std::min(bounds.top,p.y); bounds.bottom=std::max(bounds.bottom,p.y);}
+        m.from={bounds.left,bounds.top}; m.to={bounds.right,bounds.bottom};
+        auto shifted=rotateShapePoint(m,m.points[fixed]);
+        LONG dx=fixedWorld.x-shifted.x,dy=fixedWorld.y-shifted.y;
+        m.from.x+=dx; m.to.x+=dx; m.from.y+=dy; m.to.y+=dy;
+        for(auto &p:m.points) {p.x+=dx;p.y+=dy;}
+    }
+    else if(part==MarkPart::Rotation && m.shape!=ScreenshotShape::None) {
+        double cx=(m.from.x+m.to.x)/2.0,cy=(m.from.y+m.to.y)/2.0;
+        if(std::hypot(position.x-cx,position.y-cy)<1) return m;
+        double a=std::atan2(origin.y-cy,origin.x-cx),b=std::atan2(position.y-cy,position.x-cx);
+        m.rotation+=(b-a)*180/3.141592653589793;
+        if(snapRotation) m.rotation=std::round(m.rotation/15)*15;
+        m.rotation=std::remainder(m.rotation,360);
+    }
+    else if(part==MarkPart::Rotation && (m.isText() || (m.isLine() && !m.label.empty()))) {
        if(position.x==origin.x && position.y==origin.y) return m;
        auto text=m.isText()?m:screenshotArrowLabel(m);
        auto r=plainTextBounds(text);
@@ -1767,13 +2062,34 @@ ScreenshotMark dragScreenshotMark(const ScreenshotMark &original, MarkPart part,
    }
    else if(part==MarkPart::Start || part==MarkPart::End)
    {
+        origin=rotateShapePoint(original,origin,-1);
+        position=rotateShapePoint(original,position,-1);
        (part==MarkPart::Start?m.fromNumber:m.toNumber)=0;
        (part==MarkPart::Start?m.fromLink:m.toLink)={};
        auto &endpoint=part==MarkPart::Start?m.from:m.to;
        endpoint.x=std::clamp(endpoint.x+position.x-origin.x,0L,LONG(width-1));
        endpoint.y=std::clamp(endpoint.y+position.y-origin.y,0L,LONG(height-1));
        endpoint=constrainScreenshotShape(m.shape,part==MarkPart::Start?m.to:m.from,endpoint,width,height);
+        if(m.shape!=ScreenshotShape::None && !m.points.empty()) {
+            if(m.from.x==m.to.x || m.from.y==m.to.y) return original;
+            // Resize the entire recognized outline, not just a pencil endpoint.
+            // Keep the opposite corner fixed, including when dragging across it.
+            double oldWidth=original.to.x-original.from.x,oldHeight=original.to.y-original.from.y;
+            for(auto &point:m.points) {
+                double u=oldWidth?(point.x-original.from.x)/oldWidth:0;
+                double v=oldHeight?(point.y-original.from.y)/oldHeight:0;
+                point={LONG(std::lround(m.from.x+u*(m.to.x-m.from.x))),
+                       LONG(std::lround(m.from.y+v*(m.to.y-m.from.y)))};
+            }
+        }
        if(m.freehand && !m.points.empty()) (part==MarkPart::Start?m.points.front():m.points.back())=endpoint;
+        if(m.shape!=ScreenshotShape::None && m.rotation!=0) {
+            auto fixedBefore=rotateShapePoint(original,part==MarkPart::Start?original.to:original.from);
+            auto fixedAfter=rotateShapePoint(m,part==MarkPart::Start?m.to:m.from);
+            LONG dx=fixedBefore.x-fixedAfter.x,dy=fixedBefore.y-fixedAfter.y;
+            m.from.x+=dx; m.to.x+=dx; m.from.y+=dy; m.to.y+=dy;
+            for(auto &p:m.points) {p.x+=dx;p.y+=dy;}
+        }
    }
    return m;
 }
@@ -15,7 +15,7 @@ void showScreenshot(ScreenshotHost &);
 void showScreenshotEditor(ScreenshotHost &,const Clip &);
 enum class LineStyle { Solid, Dotted, Dashed, DashDot };
 enum class LineEnds { End, Start, Both, None };
-enum class ScreenshotShape { None, Rectangle, Circle, Ellipse };
+enum class ScreenshotShape { None, Rectangle, Circle, Ellipse, Triangle, Trapezoid };
 struct ScreenshotOffset { double x, y; };
 struct ScreenshotLink {
    unsigned long long target{};
@@ -40,7 +40,7 @@ struct ScreenshotMark {
    unsigned long long id{};
    ScreenshotLink fromLink, toLink;
    bool isText() const { return !text.empty(); }
-    bool isHighlight() const { return !points.empty() && !freehand; }
+    bool isHighlight() const { return !points.empty() && !freehand && shape==ScreenshotShape::None; }
    bool isLine() const { return !number && !isText() && !isHighlight() && shape==ScreenshotShape::None; }
 };
 class ScreenshotHistory {
@@ -55,7 +55,7 @@ class ScreenshotHistory {
 void resolveScreenshotLinks(std::vector<ScreenshotMark> &);
 void linkScreenshotEndpoint(ScreenshotMark &, bool start, POINT drop,
                            std::vector<ScreenshotMark> &, double tolerance);
-enum class MarkPart { None, Body, Start, End, Radius, Thickness, Rotation, Label };
+enum class MarkPart { None, Body, Start, End, Radius, Thickness, Rotation, Label, Vertex0, Vertex1, Vertex2 };
 POINT screenshotThicknessHandle(const ScreenshotMark &, double clearance = 16);
 ScreenshotMark cloneScreenshotMark(const ScreenshotMark &, const std::vector<ScreenshotMark> &, int width, int height);
 int nextScreenshotNumber(const std::vector<ScreenshotMark> &);
@@ -65,6 +65,7 @@ ScreenshotMark dragScreenshotMark(const ScreenshotMark &, MarkPart, POINT origin
 POINT constrainScreenshotShape(ScreenshotShape, POINT anchor, POINT position, int width, int height);
 RECT screenshotTextBounds(const ScreenshotMark &);
 POINT screenshotTextRotationHandle(const ScreenshotMark &, double clearance=24);
+POINT screenshotShapeRotationHandle(const ScreenshotMark &, double clearance=32);
 ScreenshotMark screenshotArrowLabel(const ScreenshotMark &);
 // Render at source resolution; never reads or writes the system clipboard.
 Clip screenshotClip(HDC source, int width, int height, const std::vector<ScreenshotMark> &marks);
@@ -50,6 +50,30 @@ void registerScreenshotNotifications()
    // Notify the shell that notification identity/activation registration changed.
    SHChangeNotify(SHCNE_ASSOCCHANGED,SHCNF_IDLIST,nullptr,nullptr);
 }
+HANDLE startScreenshotNotificationRegistration()
+{
+    auto path=std::filesystem::path(executable()).parent_path()/L"KSwitcher.Screenshot.exe";
+    auto command=L"\""+path.wstring()+L"\" --register-notifications";
+    STARTUPINFOW startup{sizeof(startup)};
+    startup.dwFlags=STARTF_USESHOWWINDOW; startup.wShowWindow=SW_HIDE;
+    PROCESS_INFORMATION process{};
+    if(!CreateProcessW(path.c_str(),command.data(),nullptr,nullptr,FALSE,CREATE_NO_WINDOW,
+                       nullptr,path.parent_path().c_str(),&startup,&process))
+        throw std::runtime_error(utf8(lastError(L"Cannot start notification registration helper")));
+    CloseHandle(process.hThread);
+    return process.hProcess;
+}
+void registerScreenshotNotificationsInHelper()
+{
+    auto process=startScreenshotNotificationRegistration();
+    auto wait=WaitForSingleObject(process,10000);
+    DWORD code=ERROR_GEN_FAILURE;
+    bool completed=wait==WAIT_OBJECT_0 && GetExitCodeProcess(process,&code);
+    CloseHandle(process);
+    if(!completed || code)
+        throw std::runtime_error(completed ? "Notification registration helper failed: "+std::to_string(code)
+                                          : "Notification registration helper did not complete within 10 seconds");
+}
 bool validScreenshotToken(const std::wstring &id)
 {
    if(id.size()!=36) return false;
@@ -1,5 +1,6 @@
 #include "screenshot.h"
 #include "screenshot_notifications.h"
+#include "storage.h"
 #include <commctrl.h>
 #include <shellapi.h>
 #include <roapi.h>
@@ -49,6 +50,18 @@ int WINAPI wWinMain(HINSTANCE instance,HINSTANCE,PWSTR,int)
    std::wstring token;
    bool autoOpenEditor=false, writeLog=false;
    int argc{}; auto argv=CommandLineToArgvW(GetCommandLineW(),&argc);
+    if(argc==3 && std::wstring(argv[1])==L"--clipboard-snapshot") {
+        std::filesystem::path request=argv[2]; LocalFree(argv);
+        return ks::runClipboardSnapshot(request);
+    }
+    if(argc==3 && (std::wstring(argv[1])==L"--capture-history" || std::wstring(argv[1])==L"--history-ocr")) {
+        bool ocr=std::wstring(argv[1])==L"--history-ocr";
+        std::filesystem::path request=argv[2]; LocalFree(argv);
+        auto initialized=CoInitializeEx(nullptr,COINIT_MULTITHREADED);
+        if(FAILED(initialized)) return 1;
+        int result=ocr ? ks::runHistoryOcr(request) : ks::runImageHistoryCapture(request);
+        CoUninitialize(); return result;
+    }
    if(argc>1 && std::wstring(argv[argc-1])==L"--write-log") {
        writeLog=true; --argc;
        ks::setLoggingEnabled(true);
@@ -206,7 +206,7 @@ bool notifyUpdateAvailable(const std::wstring &version)
 {
    try {
        // Reuse the screenshot notification identity, Windows settings and COM activator.
-        registerScreenshotNotifications();
+        registerScreenshotNotificationsInHelper();
        ComPtr<Notifications::IToastNotificationManagerStatics> manager;
        String managerClass(L"Windows.UI.Notifications.ToastNotificationManager");
        check(RoGetActivationFactory(managerClass.value,IID_PPV_ARGS(&manager)));
@@ -4,6 +4,10 @@ namespace ks {
 bool notifyScreenshot(const Clip &);
 std::string screenshotNotificationError();
 void registerScreenshotNotifications();
+// Caller owns the returned process handle; the helper exits after registration.
+HANDLE startScreenshotNotificationRegistration();
+// For background notification workers only; bounded wait, never on the UI thread.
+void registerScreenshotNotificationsInHelper();
 int runScreenshotToastActivator();
 DWORD startScreenshotActivationListener();
 bool validScreenshotToken(const std::wstring &);
@@ -4,10 +4,27 @@
 #include <algorithm>
 #include <set>
 #include <sstream>
+#include <wincrypt.h>

 namespace ks
 {
 using Json = nlohmann::json;
+std::wstring snippetId(const Snippet &snippet)
+{
+    if (!snippet.id.empty()) return snippet.id;
+    // Deterministic migration of pre-ID profiles on every existing device.
+    std::wstring id = L"legacy-";
+    const wchar_t *hex = L"0123456789abcdef";
+    for (unsigned char c : utf8(lower(snippet.trigger))) { id += hex[c >> 4]; id += hex[c & 15]; }
+    return id;
+}
+std::wstring newSnippetId()
+{
+    GUID guid{}; wchar_t text[40]{};
+    if (FAILED(CoCreateGuid(&guid))) throw std::runtime_error("Cannot create snippet ID.");
+    StringFromGUID2(guid, text, 40);
+    return text;
+}
 namespace
 {
 Bytes jsonBytes(const Json &j)
@@ -92,6 +109,19 @@ void validateSettings(const Settings &s)
            throw std::runtime_error("Unsupported auto-correction language");
    if (s.autoNever.size() > 10000 || s.autoExcluded.size() > 1000)
        throw std::runtime_error("Too many auto-correction exceptions");
+    if (s.autoReplacements.size() > 10000)
+        throw std::runtime_error("Too many automatic replacements");
+    for (const auto &[from, to] : s.autoReplacements)
+    {
+        bool valid = false;
+        for (auto alphabet : {L"abcdefghijklmnopqrstuvwxyz", L"абвгґдеєжзиіїйклмнопрстуфхцчшщьюя",
+                              L"абвгдеёжзийклмнопрстуфхцчшщъыьэюя"})
+            valid |= !from.empty() && !to.empty() && from.size() <= 32 && to.size() <= 32 &&
+                     from == lower(from) && to == lower(to) && from != to &&
+                     from.find_first_not_of(alphabet) == from.npos && to.find_first_not_of(alphabet) == to.npos;
+        if (!valid)
+            throw std::runtime_error("Replacement pairs must be different lowercase words of 1-32 letters in the same language");
+    }
    for (const auto &[language, words] : s.autoWords)
    {
        std::wstring alphabet = language == L"en" ? L"abcdefghijklmnopqrstuvwxyz" :
@@ -107,8 +137,14 @@ void validateSettings(const Settings &s)
        s.maxImageMiB > 64)
        throw std::runtime_error("History limits: 10–10000 items, 1–2048 MiB total, 1–64 MiB per image");
    std::set<std::wstring> seen;
+    std::set<std::wstring> ids;
+    for (const auto &id : s.snippetTombstones)
+        if (id.empty() || id.size() > 600 || !ids.insert(id).second)
+            throw std::runtime_error("Invalid snippet deletion record.");
    for (const auto &snippet : s.snippets)
    {
+        auto id = snippetId(snippet);
+        if (id.size() > 600 || !ids.insert(id).second) throw std::runtime_error("Duplicate snippet ID or deleted snippet.");
        if (snippet.trigger.size() < 2 || snippet.trigger.size() > 64 ||
            snippet.trigger.find_first_of(L"\r\n\t ") != snippet.trigger.npos)
            throw std::runtime_error("Snippet triggers must contain 2–64 characters without whitespace");
@@ -150,6 +186,15 @@ Settings decodeSettings(const Bytes &bytes, const std::vector<Layout> &layouts)
    s.elevatedAutostart = j.value("autostartAsAdministrator", false);
    s.awake = j.value("preventScreenLock", false);
    s.autoCorrect = j.value("autoCorrectLayout", false);
+    s.autoReplace = j.value("autoCorrectReplace", false);
+    s.autoTypos = j.value("autoCorrectTypos", false);
+    if (j.contains("autoCorrectReplacements"))
+        for (auto &[from, to] : j.at("autoCorrectReplacements").items())
+        {
+            auto key = lower(wide(from));
+            if (!s.autoReplacements.emplace(key, lower(wide(to.get<std::string>()))).second)
+                throw std::runtime_error("Duplicate automatic replacement");
+        }
    s.autoMaxRank = j.value("autoCorrectMaxRank", 0);
    s.autoMinLength = j.value("autoCorrectMinLength", 3);
    s.autoPrefixChars = str(j, "autoCorrectPrefixChars", s.autoPrefixChars);
@@ -203,7 +248,13 @@ Settings decodeSettings(const Bytes &bytes, const std::vector<Layout> &layouts)
    }
    if (j.contains("snippets"))
        for (auto &sn : j.at("snippets"))
-            s.snippets.push_back({str(sn, "trigger"), str(sn, "text")});
+        {
+            Snippet item{str(sn, "trigger"), str(sn, "text"), str(sn, "id")};
+            item.id = snippetId(item);
+            s.snippets.push_back(std::move(item));
+        }
+    if (j.contains("snippetTombstones"))
+        for (const auto &id : j.at("snippetTombstones")) s.snippetTombstones.push_back(wide(id.get<std::string>()));
    validateSettings(s);
    return s;
 }
@@ -240,6 +291,11 @@ Bytes encodeSettings(const Settings &s)
    for (auto &id : s.cycle)
        j["layouts"].push_back(utf8(id));
    j["autoCorrectLayout"] = s.autoCorrect;
+    j["autoCorrectReplace"] = s.autoReplace;
+    j["autoCorrectTypos"] = s.autoTypos;
+    j["autoCorrectReplacements"] = Json::object();
+    for (const auto &[from, to] : s.autoReplacements)
+        j["autoCorrectReplacements"][utf8(from)] = utf8(to);
    j["autoCorrectMaxRank"] = s.autoMaxRank;
    j["autoCorrectMinLength"] = s.autoMinLength;
    j["autoCorrectPrefixChars"] = utf8(s.autoPrefixChars);
@@ -264,7 +320,9 @@ Bytes encodeSettings(const Settings &s)
        j["layoutHotkeys"].push_back({{"layoutId", utf8(s.directIds[i])}, {"hotkey", utf8(s.direct[i])}});
    j["snippets"] = Json::array();
    for (auto &sn : s.snippets)
-        j["snippets"].push_back({{"trigger", utf8(sn.trigger)}, {"text", utf8(sn.text)}});
+        j["snippets"].push_back({{"trigger", utf8(sn.trigger)}, {"text", utf8(sn.text)}, {"id", utf8(snippetId(sn))}});
+    j["snippetTombstones"] = Json::array();
+    for (const auto &id : s.snippetTombstones) j["snippetTombstones"].push_back(utf8(id));
    j["excludedApps"] = Json::array();
    for (auto &name : s.excluded)
        j["excludedApps"].push_back(utf8(name));
@@ -286,6 +344,20 @@ Bytes encodeClip(const Clip &clip)
    }
    return b;
 }
+Bytes selectionClipboardIdentity(const Clip &clip)
+{
+    auto normalized = clip;
+    // GlobalSize includes allocation slack. A clipboard relay may allocate a
+    // different-sized block for the same NUL-terminated Unicode string.
+    for (auto &format : normalized.formats)
+        if (format.id == CF_UNICODETEXT)
+            format = textClip(clip.text()).formats.front();
+    std::sort(normalized.formats.begin(), normalized.formats.end(), [](const Format &a, const Format &b)
+    {
+        return std::tie(a.name, a.id) < std::tie(b.name, b.id);
+    });
+    return encodeClip(normalized);
+}
 Clip decodeClip(const Bytes &b)
 {
    size_t p = 0;
@@ -317,9 +389,17 @@ Clip decodeClip(const Bytes &b)
 History::History(const std::filesystem::path &folder) : folder_(folder)
 {
    std::filesystem::create_directories(folder_);
+    loadIndex();
+}
+void History::loadIndex()
+{
+    std::vector<Entry> loaded;
    auto index = folder_ / L"index.dat";
    if (!std::filesystem::exists(index))
+    {
+        entries_.clear();
        return;
+    }
    auto j = parse(unprotect(readFile(index, 16 * 1024 * 1024)));
    if (!j.is_array() || j.size() > 10000)
        throw std::runtime_error("Invalid history index");
@@ -334,8 +414,169 @@ History::History(const std::filesystem::path &folder) : folder_(folder)
                   e.value("image", false),
                   e.value("files", false), e.value("ocrState", e.value("image", false) ? 1 : 0),
                   str(e, "ocrProfile", L"windows")};
+        if (e.value("fingerprintVersion", 0) == 1) {
+            item.contentHash = e.value("contentHash", std::string{});
+            item.imageHash = e.value("imageHash", std::string{});
+            item.pixelHash = e.value("pixelHash", std::string{});
+        }
        if (validId(item.id) && std::filesystem::exists(folder_ / (item.id + L".dat")))
-            entries_.push_back(std::move(item));
+            loaded.push_back(std::move(item));
+    }
+    entries_ = std::move(loaded);
+}
+void History::reload() { std::lock_guard lock(mutex_); loadIndex(); }
+void ClipboardSnapshot::cleanup() noexcept
+{
+    if (request_.empty()) return;
+    std::error_code ignored;
+    for (const auto *suffix : {L"", L".snapshot", L".result"})
+        std::filesystem::remove(std::filesystem::path(request_.wstring() + suffix), ignored);
+    request_.clear();
+}
+ClipboardSnapshot::~ClipboardSnapshot() { cleanup(); }
+DWORD ClipboardSnapshot::run(bool restore, DWORD sequence)
+{
+    atomicWrite(request_, protect(jsonBytes(Json{{"schema", 1}, {"restore", restore}, {"sequence", sequence}})));
+    auto helper = std::filesystem::path(executable()).parent_path() / L"KSwitcher.Screenshot.exe";
+    auto command = L"\"" + helper.wstring() + L"\" --clipboard-snapshot \"" + request_.wstring() + L"\"";
+    STARTUPINFOW startup{sizeof(startup)};
+    startup.dwFlags = STARTF_USESHOWWINDOW; startup.wShowWindow = SW_HIDE;
+    PROCESS_INFORMATION process{};
+    if (!CreateProcessW(helper.c_str(), command.data(), nullptr, nullptr, FALSE, CREATE_NO_WINDOW,
+                        nullptr, helper.parent_path().c_str(), &startup, &process))
+        throw std::runtime_error("Cannot start clipboard snapshot helper");
+    CloseHandle(process.hThread);
+    auto wait = WaitForSingleObject(process.hProcess, 10000);
+    DWORD result = ERROR_GEN_FAILURE;
+    if (wait != WAIT_OBJECT_0)
+    {
+        TerminateProcess(process.hProcess, ERROR_TIMEOUT);
+        WaitForSingleObject(process.hProcess, INFINITE);
+    }
+    GetExitCodeProcess(process.hProcess, &result);
+    CloseHandle(process.hProcess);
+    if (wait != WAIT_OBJECT_0 || result) throw std::runtime_error("Clipboard snapshot helper failed");
+    return parse(unprotect(readFile(request_.wstring() + L".result", 4096))).at("sequence").get<DWORD>();
+}
+void ClipboardSnapshot::capture(HWND window, DWORD sequence)
+{
+    cleanup();
+    clip_ = {};
+    if (!IsClipboardFormatAvailable(CF_DIB) && !IsClipboardFormatAvailable(CF_DIBV5) &&
+        !IsClipboardFormatAvailable(CF_BITMAP) && !IsClipboardFormatAvailable(RegisterClipboardFormatW(L"PNG")))
+    {
+        clip_ = readClipboard(window, 64 * 1024 * 1024, ClipboardRead::WithoutImages, sequence);
+        return;
+    }
+    request_ = std::filesystem::temp_directory_path() / (L"ks-clipboard-" + newSnippetId() + L".request");
+    try { run(false, sequence); }
+    catch (...) { cleanup(); throw; }
+}
+DWORD ClipboardSnapshot::restore(HWND window, DWORD sequence)
+{
+    return request_.empty() ? writeClipboardGuarded(window, clip_, sequence) : run(true, sequence);
+}
+int runClipboardSnapshot(const std::filesystem::path &request)
+{
+    try
+    {
+        if (!request.is_absolute() || !request.filename().wstring().starts_with(L"ks-clipboard-") ||
+            request.extension() != L".request") return 1;
+        auto job = parse(unprotect(readFile(request, 4096)));
+        if (job.at("schema") != 1) return 1;
+        auto sequence = job.at("sequence").get<DWORD>();
+        const auto snapshot = request.wstring() + L".snapshot";
+        if (job.at("restore").get<bool>())
+        {
+            auto clip = decodeClip(unprotect(readFile(snapshot, 70 * 1024 * 1024)));
+            HWND window = CreateWindowExW(0, L"STATIC", L"", 0, 0, 0, 0, 0, HWND_MESSAGE, nullptr, nullptr, nullptr);
+            if (!window) return 1;
+            struct WindowCleanup { HWND window; ~WindowCleanup() { DestroyWindow(window); } } cleanup{window};
+            sequence = writeClipboardGuarded(window, clip, sequence);
+        }
+        else
+        {
+            auto clip = readClipboard(nullptr, 64 * 1024 * 1024, ClipboardRead::All, sequence);
+            if (sequence != GetClipboardSequenceNumber()) return 2;
+            atomicWrite(snapshot, protect(encodeClip(clip)));
+        }
+        atomicWrite(request.wstring() + L".result", protect(jsonBytes(Json{{"sequence", sequence}})));
+        return 0;
+    }
+    catch (...) { return 1; }
+}
+bool History::captureImage(DWORD sequence, const std::wstring &app, const Settings &settings)
+{
+    // Serialize helper index changes with all resident history mutations. Only
+    // metadata is reloaded: GetClipboardData's image allocations die with the child.
+    std::lock_guard lock(mutex_);
+    if (sequence != GetClipboardSequenceNumber()) return false;
+    auto request = std::filesystem::absolute(folder_) / (L"capture-" + newSnippetId() + L".request");
+    struct Cleanup {
+        std::filesystem::path path;
+        ~Cleanup() { std::error_code ignored; std::filesystem::remove(path, ignored); }
+    } cleanup{request};
+    Json job{{"schema", 1}, {"sequence", sequence}, {"app", utf8(app)},
+             {"settings", Json::parse(encodeSettings(settings))}};
+    atomicWrite(request, protect(jsonBytes(job)));
+    auto helper = std::filesystem::path(executable()).parent_path() / L"KSwitcher.Screenshot.exe";
+    auto command = L"\"" + helper.wstring() + L"\" --capture-history \"" + request.wstring() + L"\"";
+    STARTUPINFOW startup{sizeof(startup)};
+    startup.dwFlags = STARTF_USESHOWWINDOW; startup.wShowWindow = SW_HIDE;
+    PROCESS_INFORMATION process{};
+    if (!CreateProcessW(helper.c_str(), command.data(), nullptr, nullptr, FALSE, CREATE_NO_WINDOW,
+                        nullptr, helper.parent_path().c_str(), &startup, &process))
+        throw std::runtime_error(utf8(lastError(L"Cannot start image history helper")));
+    CloseHandle(process.hThread);
+    auto wait = WaitForSingleObject(process.hProcess, 30000);
+    DWORD result = ERROR_GEN_FAILURE;
+    if (wait != WAIT_OBJECT_0)
+    {
+        // Never release the index lock while a timed-out child can still write it.
+        TerminateProcess(process.hProcess, ERROR_TIMEOUT);
+        WaitForSingleObject(process.hProcess, INFINITE);
+    }
+    GetExitCodeProcess(process.hProcess, &result);
+    CloseHandle(process.hProcess);
+    loadIndex(); // Also reconcile any completed atomic save before a child failure.
+    if (wait != WAIT_OBJECT_0) throw std::runtime_error("Image history helper timed out");
+    if (result == 2) return false;
+    if (result == 3) throw std::runtime_error("Clipboard exceeds the configured size limit");
+    if (result) throw std::runtime_error("Image history helper failed: " + std::to_string(result));
+    return true;
+}
+int runImageHistoryCapture(const std::filesystem::path &request)
+{
+    try
+    {
+        if (!request.is_absolute() || !request.filename().wstring().starts_with(L"capture-") ||
+            request.extension() != L".request") return 1;
+        auto job = parse(unprotect(readFile(request, 4 * 1024 * 1024)));
+        if (job.at("schema") != 1) return 1;
+        auto sequence = job.at("sequence").get<DWORD>();
+        auto settings = decodeSettings(jsonBytes(job.at("settings")), readLayouts());
+        auto valid = [&] {
+            return settings.history && sequence == GetClipboardSequenceNumber() &&
+                !IsClipboardFormatAvailable(RegisterClipboardFormatW(L"ExcludeClipboardContentFromMonitorProcessing")) &&
+                !IsClipboardFormatAvailable(RegisterClipboardFormatW(L"Clipboard Viewer Ignore"));
+        };
+        if (!valid()) return 2;
+        if (!IsClipboardFormatAvailable(CF_DIB) && !IsClipboardFormatAvailable(CF_DIBV5) &&
+            !IsClipboardFormatAvailable(CF_BITMAP) &&
+            !IsClipboardFormatAvailable(RegisterClipboardFormatW(L"PNG"))) return 2;
+        auto clip = readClipboard(nullptr, size_t(settings.maxImageMiB) * 1024 * 1024);
+        if (!valid()) return 2;
+        for (const auto &format : clip.formats)
+            if (format.name == L"CanIncludeInClipboardHistory" && format.data.size() >= 4 &&
+                !format.data[0] && !format.data[1] && !format.data[2] && !format.data[3]) return 2;
+        History history(request.parent_path());
+        if (!valid()) return 2;
+        history.add(clip, str(job, "app"), settings);
+        return 0;
+    }
+    catch (const std::exception &e)
+    {
+        return std::string(e.what()) == "Clipboard exceeds the configured size limit" ? 3 : 1;
    }
 }
 void History::saveIndex()
@@ -349,7 +590,9 @@ void History::saveIndex()
                     {"at", e.at},
                     {"pinned", e.pinned},
                     {"image", e.image},
-                     {"files", e.files}, {"ocrState", e.ocrState}, {"ocrProfile", utf8(e.ocrProfile)}});
+                     {"files", e.files}, {"ocrState", e.ocrState}, {"ocrProfile", utf8(e.ocrProfile)},
+                     {"fingerprintVersion", 1}, {"contentHash", e.contentHash},
+                     {"imageHash", e.imageHash}, {"pixelHash", e.pixelHash}});
    atomicWrite(folder_ / L"index.dat", protect(jsonBytes(j)));
 }
 std::vector<Entry> History::entries() const
@@ -382,12 +625,10 @@ void History::prune(const Settings &s)
        entries_.erase(entries_.begin() + i);
    }
 }
-bool sameClipboardImage(const Clip &a, const Clip &b)
+static const Format *clipboardImageFormat(const Clip &c)
 {
    // OLE DataObject / Ole Private Data change when Snipping Tool republishes
    // the same capture. They are transport metadata, not image identity.
-    auto image = [](const Clip &c) -> const Format *
-    {
        if (!c.text().empty())
            return nullptr;
        for (const auto &f : c.formats)
@@ -401,8 +642,42 @@ bool sameClipboardImage(const Clip &a, const Clip &b)
                if (f.id == id && !f.data.empty())
                    return &f;
        return nullptr;
-    };
-    const auto *left = image(a), *right = image(b);
+}
+static std::string clipboardHash(const Bytes &bytes)
+{
+    struct Hash {
+        HCRYPTPROV provider{}; HCRYPTHASH hash{};
+        ~Hash() { if (hash) CryptDestroyHash(hash); if (provider) CryptReleaseContext(provider, 0); }
+    } state;
+    if (!CryptAcquireContextW(&state.provider, nullptr, nullptr, PROV_RSA_AES, CRYPT_VERIFYCONTEXT) ||
+        !CryptCreateHash(state.provider, CALG_SHA_256, 0, 0, &state.hash) ||
+        !CryptHashData(state.hash, bytes.data(), static_cast<DWORD>(bytes.size()), 0))
+        throw std::runtime_error("Cannot hash clipboard data");
+    BYTE digest[32]{}; DWORD size = sizeof(digest);
+    if (!CryptGetHashParam(state.hash, HP_HASHVAL, digest, &size, 0) || size != sizeof(digest))
+        throw std::runtime_error("Cannot read clipboard hash");
+    static constexpr char hex[] = "0123456789abcdef";
+    std::string result; result.reserve(64);
+    for (auto b : digest) { result += hex[b >> 4]; result += hex[b & 15]; }
+    return result;
+}
+static void imageFingerprints(Entry &entry, const Clip &clip, bool decodePixels = true)
+{
+    const auto *image = clipboardImageFormat(clip);
+    if (!image) return;
+    if (entry.imageHash.empty())
+        entry.imageHash = std::to_string(image->id) + ":" + utf8(image->name) + ":" + clipboardHash(image->data);
+    if (!decodePixels) return;
+    try {
+        auto pixels = decodeImage(clip);
+        entry.pixelHash = std::to_string(pixels.width) + "x" + std::to_string(pixels.height) + ":" + clipboardHash(pixels.bgra);
+    } catch (const std::exception &) {
+        // Undecodable images can still be compared by their original bytes.
+    }
+}
+bool sameClipboardImage(const Clip &a, const Clip &b)
+{
+    const auto *left = clipboardImageFormat(a), *right = clipboardImageFormat(b);
    if (!left || !right)
        return false;
    if (left->id == right->id && left->name == right->name && left->data == right->data)
@@ -426,16 +701,41 @@ void History::add(const Clip &clip, const std::wstring &app, const Settings &s)
    auto data = encodeClip(clip);
    if (data.size() > uint64_t(s.maxImageMiB) * 1024 * 1024)
        return;
+    bool image = false, files = false;
+    for (const auto &f : clip.formats)
+    {
+        image |= f.id == CF_DIB || f.id == CF_DIBV5 || f.name == L"PNG";
+        files |= f.id == CF_HDROP;
+    }
    std::lock_guard lock(mutex_);
-    // Compare only the newest record; never keep image payloads in the resident index.
-    if (!entries_.empty())
+    Entry fingerprints;
+    fingerprints.contentHash = clipboardHash(data);
+    if (!entries_.empty() && entries_.front().contentHash == fingerprints.contentHash)
+        return;
+    imageFingerprints(fingerprints, clip, false);
+    if (!entries_.empty() && !fingerprints.imageHash.empty() && entries_.front().imageHash == fingerprints.imageHash)
+        return;
+    imageFingerprints(fingerprints, clip);
+    // Different payload kinds cannot be duplicates. Consult the index first so
+    // copying text after a screenshot never loads/decrypts the previous image.
+    if (!entries_.empty() && entries_.front().image == image && entries_.front().files == files)
    {
        try
        {
-            auto previous = load(entries_.front().id);
-            if (encodeClip(previous) == data || sameClipboardImage(previous, clip))
+            auto &previous = entries_.front();
+            bool migrated = previous.contentHash.empty();
+            if (migrated) {
+                auto oldClip = load(previous.id);
+                previous.contentHash = clipboardHash(encodeClip(oldClip));
+                imageFingerprints(previous, oldClip);
+            }
+            if (previous.contentHash == fingerprints.contentHash ||
+                (!fingerprints.imageHash.empty() && previous.imageHash == fingerprints.imageHash) ||
+                (!fingerprints.pixelHash.empty() && previous.pixelHash == fingerprints.pixelHash)) {
+                if (migrated) saveIndex();
                return;
            }
+        }
        catch (...)
        {
        }
@@ -449,12 +749,6 @@ void History::add(const Clip &clip, const std::wstring &app, const Settings &s)
    auto encrypted = protect(data);
    atomicWrite(folder_ / (id + L".dat"), encrypted);
    auto text = clip.text();
-    bool image = false, files = false;
-    for (auto &f : clip.formats)
-    {
-        image |= f.id == CF_DIB || f.id == CF_DIBV5 || f.name == L"PNG";
-        files |= f.id == CF_HDROP;
-    }
    if (text.empty())
        text = files ? L"[Files]" : image ? L"[Image]" : L"[Clipboard data]";
    for (auto &c : text)
@@ -467,7 +761,8 @@ void History::add(const Clip &clip, const std::wstring &app, const Settings &s)
    entries_.insert(entries_.begin(),
                    Entry{id, text, app, encrypted.size(),
                          (uint64_t(now.dwHighDateTime) << 32) | now.dwLowDateTime, false, image, files,
-                          image ? 1 : 0, ocrProfile(s)});
+                          image ? 1 : 0, ocrProfile(s), std::move(fingerprints.contentHash),
+                          std::move(fingerprints.imageHash), std::move(fingerprints.pixelHash)});
    prune(s);
    saveIndex();
 }
@@ -506,6 +801,103 @@ void History::clear()
        std::filesystem::remove(folder_ / (e.id + L".ocr"), ec);
    }
 }
+static Bytes historyImageJob(const std::filesystem::path &folder, const std::wstring &id,
+                             const Json &job, const std::function<bool()> &cancelled)
+{
+    if (!validId(id)) throw std::runtime_error("Invalid history ID");
+    if (cancelled && cancelled()) throw std::runtime_error("History OCR cancelled");
+    auto request = std::filesystem::absolute(folder) / (L"ocr-" + newSnippetId() + L".request");
+    auto response = request; response += L".result";
+    struct Cleanup {
+        std::filesystem::path request, response;
+        ~Cleanup() {
+            std::error_code ignored;
+            std::filesystem::remove(request, ignored);
+            std::filesystem::remove(response, ignored);
+        }
+    } cleanup{request, response};
+    atomicWrite(request, protect(jsonBytes(job)));
+    auto helper = std::filesystem::path(executable()).parent_path() / L"KSwitcher.Screenshot.exe";
+    auto command = L"\"" + helper.wstring() + L"\" --history-ocr \"" + request.wstring() + L"\"";
+    STARTUPINFOW startup{sizeof(startup)};
+    startup.dwFlags = STARTF_USESHOWWINDOW; startup.wShowWindow = SW_HIDE;
+    PROCESS_INFORMATION process{};
+    if (!CreateProcessW(helper.c_str(), command.data(), nullptr, nullptr, FALSE, CREATE_NO_WINDOW,
+                        nullptr, helper.parent_path().c_str(), &startup, &process))
+        throw std::runtime_error(utf8(lastError(L"Cannot start history OCR helper")));
+    CloseHandle(process.hThread);
+    struct Child {
+        HANDLE handle;
+        ~Child() {
+            if (WaitForSingleObject(handle, 0) != WAIT_OBJECT_0) {
+                TerminateProcess(handle, ERROR_CANCELLED);
+                WaitForSingleObject(handle, INFINITE);
+            }
+            CloseHandle(handle);
+        }
+    } child{process.hProcess};
+    auto deadline = GetTickCount64() + 60000;
+    for (;;) {
+        auto wait = WaitForSingleObject(child.handle, 100);
+        if (wait == WAIT_OBJECT_0) break;
+        if (wait != WAIT_TIMEOUT) throw std::runtime_error("Cannot wait for history OCR helper");
+        if (cancelled && cancelled()) throw std::runtime_error("History OCR cancelled");
+        if (GetTickCount64() >= deadline) throw std::runtime_error("History OCR helper timed out");
+    }
+    DWORD result{};
+    if (!GetExitCodeProcess(child.handle, &result) || result)
+        throw std::runtime_error("History OCR helper failed: " + std::to_string(result));
+    return unprotect(readFile(response, 8 * 1024 * 1024));
+}
+std::wstring History::recognizeImage(const std::wstring &id, const Settings &settings,
+                                    const std::function<bool()> &cancelled) const
+{
+    Json job{{"schema", 1}, {"id", utf8(id)}, {"tesseract", settings.useTesseract},
+             {"path", utf8(settings.tesseractPath)}, {"languages", utf8(settings.tesseractLanguages)}};
+    auto reply = parse(historyImageJob(folder_, id, job, cancelled));
+    if (reply.at("schema") != 1 || str(reply, "id") != id)
+        throw std::runtime_error("Invalid history OCR response");
+    return str(reply, "text");
+}
+Pixels History::thumbnail(const std::wstring &id, const std::function<bool()> &cancelled) const
+{
+    auto bytes = historyImageJob(folder_, id, Json{{"schema", 1}, {"id", utf8(id)}, {"thumbnail", true}}, cancelled);
+    size_t at = 0;
+    auto width = get32(bytes, at), height = get32(bytes, at);
+    if (!width || !height || width > 208 || height > 128 || bytes.size() - at != width * height * 4)
+        throw std::runtime_error("Invalid history thumbnail response");
+    bytes.erase(bytes.begin(), bytes.begin() + at);
+    return Pixels{width, height, std::move(bytes)};
+}
+int runHistoryOcr(const std::filesystem::path &request)
+{
+    try {
+        if (!request.is_absolute() || !request.filename().wstring().starts_with(L"ocr-") ||
+            request.extension() != L".request") return 1;
+        auto job = parse(unprotect(readFile(request, 1024 * 1024)));
+        auto id = str(job, "id");
+        if (job.at("schema") != 1 || !validId(id)) return 1;
+        auto clip = decodeClip(unprotect(readFile(request.parent_path() / (id + L".dat"), 80 * 1024 * 1024)));
+        if (job.value("thumbnail", false)) {
+            auto pixels = decodeImage(clip, 208, 128);
+            if (!pixels.width || !pixels.height) return 1;
+            Bytes reply;
+            put32(reply, pixels.width); put32(reply, pixels.height);
+            reply.insert(reply.end(), pixels.bgra.begin(), pixels.bgra.end());
+            atomicWrite(request.wstring() + L".result", protect(reply));
+            return 0;
+        }
+        Settings settings;
+        settings.useTesseract = job.at("tesseract").get<bool>();
+        settings.tesseractPath = str(job, "path");
+        settings.tesseractLanguages = str(job, "languages");
+        auto text = utf8(recognizeText(clip, settings));
+        if (text.size() > 1024 * 1024) return 1;
+        auto response = request; response += L".result";
+        atomicWrite(response, protect(jsonBytes(Json{{"schema", 1}, {"id", utf8(id)}, {"text", text}})));
+        return 0;
+    } catch (...) { return 1; }
+}
 bool History::saveOcr(const std::wstring &id, const std::optional<std::wstring> &text, const Settings &settings)
 {
    std::lock_guard lock(mutex_);
@@ -546,9 +938,10 @@ std::optional<std::wstring> History::ocrText(const std::wstring &id, const std::
    if (bytes.empty() || bytes.front() != 1) throw std::runtime_error("Invalid OCR text format");
    return wide(std::string(bytes.begin() + 1, bytes.end()));
 }
-std::vector<Entry> History::search(const std::wstring &query) const
+std::vector<Entry> History::search(const std::wstring &query, bool pinnedOnly) const
 {
    auto items = entries();
+    if (pinnedOnly) std::erase_if(items, [](const Entry &entry) { return !entry.pinned; });
    if (query.empty())
        return items;
    auto q = lower(query);
@@ -1,8 +1,10 @@
 #pragma once
 #include "platform.h"
 #include <mutex>
+#include <functional>
 namespace ks
 {
+struct Pixels;
 Settings loadSettings(const std::filesystem::path &, const std::vector<Layout> &);
 Settings decodeSettings(const Bytes &, const std::vector<Layout> &);
 Bytes encodeSettings(const Settings &);
@@ -15,6 +17,7 @@ struct Entry
    bool pinned{}, image{}, files{};
    int ocrState{}; // 0: legacy/not applicable, 1: pending, 2: saved, 3: failed
    std::wstring ocrProfile = L"windows";
+    std::string contentHash, imageHash, pixelHash;
 };
 class History
 {
@@ -22,21 +25,46 @@ class History
    std::vector<Entry> entries_;
    mutable std::mutex mutex_;
    void saveIndex();
+    void loadIndex();
    void prune(const Settings &);

  public:
    explicit History(const std::filesystem::path &);
+    void reload();
    std::vector<Entry> entries() const;
    Clip load(const std::wstring &id) const;
    void add(const Clip &, const std::wstring &app, const Settings &);
+    bool captureImage(DWORD sequence, const std::wstring &app, const Settings &);
+    std::wstring recognizeImage(const std::wstring &id, const Settings &,
+                                const std::function<bool()> &cancelled = {}) const;
+    Pixels thumbnail(const std::wstring &id, const std::function<bool()> &cancelled = {}) const;
    bool saveOcr(const std::wstring &id, const std::optional<std::wstring> &, const Settings &);
    std::optional<std::wstring> ocrText(const std::wstring &id, const std::wstring &profile = L"") const;
    void remove(const std::wstring &);
    void pin(const std::wstring &);
    void clear();
-    std::vector<Entry> search(const std::wstring &) const;
+    std::vector<Entry> search(const std::wstring &, bool pinnedOnly = false) const;
 };
 Bytes encodeClip(const Clip &);
+Bytes selectionClipboardIdentity(const Clip &);
 Clip decodeClip(const Bytes &);
 bool sameClipboardImage(const Clip &, const Clip &);
+int runImageHistoryCapture(const std::filesystem::path &request);
+int runHistoryOcr(const std::filesystem::path &request);
+// Image backups stay encrypted on disk and are read/written only by a short-lived helper.
+class ClipboardSnapshot
+{
+    Clip clip_;
+    std::filesystem::path request_;
+    void cleanup() noexcept;
+    DWORD run(bool restore, DWORD sequence);
+  public:
+    ClipboardSnapshot() = default;
+    ClipboardSnapshot(const ClipboardSnapshot &) = delete;
+    ClipboardSnapshot &operator=(const ClipboardSnapshot &) = delete;
+    ~ClipboardSnapshot();
+    void capture(HWND, DWORD sequence);
+    DWORD restore(HWND, DWORD sequence);
+};
+int runClipboardSnapshot(const std::filesystem::path &request);
 } // namespace ks
@@ -0,0 +1,240 @@
+#pragma once
+#include "screenshot.h"
+#include <algorithm>
+#include <cmath>
+#include <vector>
+
+namespace ks::stroke_detail {
+struct Point { double x, y; };
+inline double distance(Point a, Point b) { return std::hypot(a.x-b.x,a.y-b.y); }
+inline double length(const std::vector<Point> &p) {
+    double total=0;
+    for(size_t i=1;i<p.size();++i) total+=distance(p[i-1],p[i]);
+    return total;
+}
+// Arc-length sampling makes fitting independent of mouse speed and bounds its cost.
+inline std::vector<Point> sample(const std::vector<Point> &p, size_t count) {
+    std::vector<Point> out{p.front()};
+    double step=length(p)/(count-1), traversed=0;
+    size_t segment=1;
+    for(size_t i=1;i+1<count;++i) {
+        double target=i*step;
+        while(segment+1<p.size() && traversed+distance(p[segment-1],p[segment])<target) {
+            traversed+=distance(p[segment-1],p[segment]); ++segment;
+        }
+        double span=distance(p[segment-1],p[segment]);
+        double t=span>0?(target-traversed)/span:0;
+        out.push_back({p[segment-1].x+t*(p[segment].x-p[segment-1].x),
+                       p[segment-1].y+t*(p[segment].y-p[segment-1].y)});
+    }
+    out.push_back(p.back()); return out;
+}
+inline double segmentDistance(Point p, Point a, Point b) {
+    double dx=b.x-a.x,dy=b.y-a.y,den=dx*dx+dy*dy;
+    double t=den?std::clamp(((p.x-a.x)*dx+(p.y-a.y)*dy)/den,0.0,1.0):0;
+    return distance(p,{a.x+t*dx,a.y+t*dy});
+}
+inline double cross(Point a, Point b, Point c) { return (b.x-a.x)*(c.y-a.y)-(b.y-a.y)*(c.x-a.x); }
+}
+
+namespace ks {
+// Returns a replacement path; an empty result means no visible improvement.
+// Report recognized geometry separately from a smoothed freehand path.
+inline std::vector<POINT> improveScreenshotStroke(const std::vector<POINT> &input, ScreenshotShape *shape=nullptr,
+                                                 bool *straightLine=nullptr) {
+    if(shape) *shape=ScreenshotShape::None;
+    if(straightLine) *straightLine=false;
+    using namespace stroke_detail;
+    if(input.size()<3) return {};
+    std::vector<Point> raw;
+    for(auto p:input) if(raw.empty() || distance(raw.back(),{double(p.x),double(p.y)})>0)
+        raw.push_back({double(p.x),double(p.y)});
+    double total=length(raw);
+    if(raw.size()>=3) {
+        double span=distance(raw.front(),raw.back());
+        if(span>=24 && total<=span*1.35) {
+            double tolerance=std::clamp(span*.03,2.0,6.0),maximum=0,backtracking=0,previous=0;
+            Point a=raw.front(),b=raw.back();
+            // Check every original point so a short excursion cannot disappear in resampling.
+            for(auto p:raw) {
+                maximum=std::max(maximum,segmentDistance(p,a,b));
+                double along=((p.x-a.x)*(b.x-a.x)+(p.y-a.y)*(b.y-a.y))/span;
+                backtracking+=std::max(0.0,previous-along); previous=along;
+            }
+            double squared=0;
+            for(auto p:sample(raw,64)) { double d=segmentDistance(p,a,b); squared+=d*d; }
+            if(maximum<=tolerance && std::sqrt(squared/64)<=tolerance*.7 &&
+               backtracking<=std::max(2.0,span*.02)) {
+                if(straightLine) *straightLine=true;
+                return {input.front(),input.back()};
+            }
+        }
+    }
+    if(raw.size()<5 || total<16) return {};
+    auto points=sample(raw,128);
+    double left=points[0].x,right=left,top=points[0].y,bottom=top;
+    for(auto p:points) { left=std::min(left,p.x); right=std::max(right,p.x); top=std::min(top,p.y); bottom=std::max(bottom,p.y); }
+    double scale=std::min(right-left,bottom-top);
+    std::vector<Point> best;
+    double bestScore=1e30;
+    double gap=distance(raw.front(),raw.back());
+    if(scale>=20 && gap<=scale*.5) {
+        auto consider=[&](std::vector<Point> candidate, ScreenshotShape kind=ScreenshotShape::Rectangle) {
+            bool oval=kind==ScreenshotShape::Circle || kind==ScreenshotShape::Ellipse;
+            if(!oval && gap>scale*.22) return;
+            double perimeter=length(candidate);
+            if(total<perimeter*.82 || total>perimeter*1.25) return;
+            auto probes=sample(candidate,128);
+            double sum=0,maximum=0;
+            auto measure=[&](const std::vector<Point> &a,const std::vector<Point> &b) {
+                for(auto p:a) {
+                    double d=1e30;
+                    for(size_t i=1;i<b.size();++i) d=std::min(d,segmentDistance(p,b[i-1],b[i]));
+                    sum+=d*d; maximum=std::max(maximum,d);
+                }
+            };
+            measure(points,candidate); measure(probes,points);
+            double score=std::sqrt(sum/256);
+            if(maximum<=std::max(3.0,scale*(oval?.22:.12)) && score<=std::max(1.5,scale*(oval?.085:.055)) && score<bestScore) {
+                bestScore=score; best=std::move(candidate);
+                if(shape) *shape=kind;
+            }
+        };
+        // Fit oriented bounding boxes; testing angles also handles tilted ovals.
+        for(int degrees=0;degrees<180;degrees+=5) {
+            double angle=degrees*3.141592653589793/180,cs=std::cos(angle),sn=std::sin(angle);
+            double x0=1e30,y0=x0,x1=-x0,y1=-x0;
+            for(auto p:points) {
+                double x=p.x*cs+p.y*sn,y=-p.x*sn+p.y*cs;
+                x0=std::min(x0,x); x1=std::max(x1,x); y0=std::min(y0,y); y1=std::max(y1,y);
+            }
+            auto world=[&](double x,double y)->Point { return {x*cs-y*sn,x*sn+y*cs}; };
+            consider({world(x0,y0),world(x1,y0),world(x1,y1),world(x0,y1),world(x0,y0)});
+            double rx=(x1-x0)/2,ry=(y1-y0)/2;
+            double cx=(x0+x1)/2,cy=(y0+y1)/2;
+            std::vector<Point> local;
+            for(auto p:points) local.push_back({p.x*cs+p.y*sn,-p.x*sn+p.y*cs});
+            // Fit four sides to their supporting samples. Extremal bounds exaggerate
+            // crooked corners and can unfairly make an oval score better than a box.
+            double sides[]{x0,x1,y0,y1};
+            bool supported=true;
+            for(int iteration=0;iteration<6;++iteration) {
+                double sums[4]{}; int counts[4]{};
+                for(auto p:local) {
+                    double distances[]{std::abs(p.x-sides[0]),std::abs(p.x-sides[1]),
+                                       std::abs(p.y-sides[2]),std::abs(p.y-sides[3])};
+                    auto side=std::min_element(distances,distances+4)-distances;
+                    sums[side]+=side<2?p.x:p.y; ++counts[side];
+                }
+                for(int side=0;side<4;++side) {
+                    if(counts[side]<10) { supported=false; break; }
+                    sides[side]=sums[side]/counts[side];
+                }
+                if(!supported) break;
+            }
+            if(supported && sides[1]-sides[0]>=16 && sides[3]-sides[2]>=16)
+                consider({world(sides[0],sides[2]),world(sides[1],sides[2]),
+                          world(sides[1],sides[3]),world(sides[0],sides[3]),world(sides[0],sides[2])});
+            // Fit the whole gesture instead of letting a single mouse wobble set the bounds.
+            auto error=[&](double x,double y,double a,double b) {
+                if(a<8 || b<8) return 1e30;
+                double sum=0;
+                for(auto p:local) {
+                    double u=(p.x-x)/a,v=(p.y-y)/b,r=std::hypot(u,v);
+                    double normal=std::hypot(u/a,v/b);
+                    double d=normal>1e-9?(r-1)*r/normal:std::min(a,b);
+                    sum+=d*d;
+                }
+                return sum;
+            };
+            double fit=error(cx,cy,rx,ry),step=std::max(rx,ry)*.08;
+            for(int iteration=0;iteration<10;++iteration) {
+                for(int parameter=0;parameter<4;++parameter) for(int sign:{-1,1}) {
+                    double values[]{cx,cy,rx,ry}; values[parameter]+=sign*step;
+                    double next=error(values[0],values[1],values[2],values[3]);
+                    if(next<fit) { fit=next; cx=values[0]; cy=values[1]; rx=values[2]; ry=values[3]; }
+                }
+                step*=.65;
+            }
+            // Require almost one complete turn, with little retracing. This admits a small
+            // closing gap or overshoot but rejects C-shaped arcs, spirals and scribbles.
+            double turn=0,travel=0;
+            for(size_t i=1;i<local.size();++i) {
+                double a=std::atan2((local[i-1].y-cy)/ry,(local[i-1].x-cx)/rx);
+                double b=std::atan2((local[i].y-cy)/ry,(local[i].x-cx)/rx);
+                double delta=std::remainder(b-a,2*3.141592653589793);
+                turn+=delta; travel+=std::abs(delta);
+            }
+            if(std::abs(turn)<5.4 || std::abs(turn)>7.1 || travel-std::abs(turn)>.65) continue;
+            // Near-circular gestures become true circles.
+            bool circle=std::abs(rx-ry)<=std::max(rx,ry)*.12;
+            if(circle) rx=ry=(rx+ry)/2;
+            std::vector<Point> oval;
+            for(int i=0;i<96;++i) {
+                double t=i*2*3.141592653589793/96;
+                oval.push_back(world(cx+rx*std::cos(t),cy+ry*std::sin(t)));
+            }
+            oval.push_back(oval.front()); consider(std::move(oval),circle?ScreenshotShape::Circle:ScreenshotShape::Ellipse);
+        }
+        auto sorted=points;
+        std::sort(sorted.begin(),sorted.end(),[](Point a,Point b){return a.x<b.x || (a.x==b.x && a.y<b.y);});
+        std::vector<Point> hull;
+        for(auto p:sorted) {
+            while(hull.size()>1 && cross(hull[hull.size()-2],hull.back(),p)<=0) hull.pop_back();
+            hull.push_back(p);
+        }
+        size_t lower=hull.size();
+        for(size_t i=sorted.size()-1;i-->0;) {
+            auto p=sorted[i];
+            while(hull.size()>lower && cross(hull[hull.size()-2],hull.back(),p)<=0) hull.pop_back();
+            hull.push_back(p);
+        }
+        hull.pop_back();
+        while(hull.size()>3) {
+            if(hull.size()==4 && bestScore>scale*.035) {
+                // Opposite edges must already be nearly parallel; retain their unequal
+                // lengths and fit a shared direction instead of accepting any quadrilateral.
+                for(size_t i=0;i<2;++i) {
+                    Point a=hull[i],b=hull[i+1],c=hull[(i+2)%4],d=hull[(i+3)%4];
+                    double ab=distance(a,b),cd=distance(c,d);
+                    if(std::min(ab,cd)<16 || std::min(ab,cd)/std::max(ab,cd)>.8) continue;
+                    Point u{(b.x-a.x)/ab,(b.y-a.y)/ab},v{(c.x-d.x)/cd,(c.y-d.y)/cd};
+                    if(u.x*v.x+u.y*v.y<.96) continue;
+                    double norm=std::hypot(u.x+v.x,u.y+v.y);
+                    Point axis{(u.x+v.x)/norm,(u.y+v.y)/norm};
+                    auto along=[&](Point p){return p.x*axis.x+p.y*axis.y;};
+                    auto across=[&](Point p){return -p.x*axis.y+p.y*axis.x;};
+                    double y0=(across(a)+across(b))/2,y1=(across(c)+across(d))/2;
+                    if(std::abs(y1-y0)<20) continue;
+                    auto fit=[&](Point p,double y)->Point {double x=along(p);return {x*axis.x-y*axis.y,x*axis.y+y*axis.x};};
+                    std::vector<Point> candidate{fit(a,y0),fit(b,y0),fit(c,y1),fit(d,y1),fit(a,y0)};
+                    consider(std::move(candidate),ScreenshotShape::Trapezoid);
+                }
+            }
+            size_t remove=0; double area=1e30;
+            for(size_t i=0;i<hull.size();++i) {
+                double a=std::abs(cross(hull[(i+hull.size()-1)%hull.size()],hull[i],hull[(i+1)%hull.size()]));
+                if(a<area) { area=a; remove=i; }
+            }
+            hull.erase(hull.begin()+remove);
+        }
+        if(hull.size()==3) { hull.push_back(hull.front()); consider(hull,ScreenshotShape::Triangle); }
+    }
+    if(best.empty()) {
+        // A small spatial filter suppresses jitter without moving endpoints or flattening broad curves.
+        best=sample(raw,size_t(std::clamp(std::ceil(total/2)+1,5.0,2048.0)));
+        auto original=best;
+        for(size_t i=1;i+1<best.size();++i)
+            best[i]={(original[i-1].x+2*original[i].x+original[i+1].x)/4,
+                     (original[i-1].y+2*original[i].y+original[i+1].y)/4};
+    }
+    std::vector<POINT> result;
+    for(auto p:best) {
+        POINT q{LONG(std::lround(p.x)),LONG(std::lround(p.y))};
+        if(result.empty() || result.back().x!=q.x || result.back().y!=q.y) result.push_back(q);
+    }
+    if(result.size()==input.size() && std::equal(result.begin(),result.end(),input.begin(),
+       [](POINT a,POINT b){return a.x==b.x && a.y==b.y;})) return {};
+    return result;
+}
+}
@@ -0,0 +1,354 @@
+#include "sync.h"
+#include "json.hpp"
+#include <winhttp.h>
+#include <wincred.h>
+#include <set>
+#include <algorithm>
+
+namespace ks
+{
+using Json = nlohmann::json;
+namespace
+{
+constexpr size_t Limit = 4 * 1024 * 1024;
+Bytes bytes(const Json &j) { auto s = j.dump(); return {s.begin(), s.end()}; }
+Json parse(const Bytes &b) { return Json::parse(b.begin(), b.end()); }
+Json configJson(const SyncConfig &c)
+{
+    return {{"enabled", c.enabled}, {"provider", utf8(c.provider)}, {"server", utf8(c.server)},
+        {"mount", utf8(c.mount)}, {"path", utf8(c.path)}, {"authMount", utf8(c.authMount)},
+        {"username", utf8(c.username)}, {"keepLocalLayouts", c.keepLocalLayouts}};
+}
+std::wstring credentialName(const SyncConfig &c)
+{
+    return L"KSwitcher.Sync/" + c.server + L"/" + c.authMount + L"/" + c.username;
+}
+bool safePath(const std::wstring &s)
+{
+    if (s.empty() || s.size() > 512 || s.front() == '/' || s.back() == '/' ||
+        s.find(L"//") != s.npos) return false;
+    return s.find_first_not_of(L"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_-/") == s.npos;
+}
+struct HttpHandle
+{
+    HINTERNET h{};
+    ~HttpHandle() { if (h) WinHttpCloseHandle(h); }
+};
+class OpenBao final : public SyncProvider
+{
+    SyncConfig config;
+    SyncTransport transport;
+    std::wstring token;
+    Json response(unsigned status, const Bytes &result, bool missing)
+    {
+        if (result.size() > Limit) throw std::runtime_error("OpenBao response is too large.");
+        if (status == 404 && missing)
+        {
+            auto j = result.empty() ? Json::object() : parse(result);
+            if (j.contains("data") && !j["data"].is_null())
+                throw std::runtime_error("Remote profile is deleted. Restore it in OpenBao first.");
+            return nullptr;
+        }
+        if (status == 401 || status == 403) throw std::runtime_error("OpenBao denied access. Check login and profile policy.");
+        if (status == 400) throw std::runtime_error("OpenBao rejected the write or its version changed. Sync again; check KV v2 configuration.");
+        if (status < 200 || status >= 300) throw std::runtime_error("OpenBao HTTP error " + std::to_string(status) + ".");
+        return result.empty() ? Json::object() : parse(result);
+    }
+    Json request(const wchar_t *method, const std::wstring &path, const Json *body = nullptr, bool missing = false)
+    {
+        if (transport)
+        {
+            auto reply = transport(method, path, token, body ? bytes(*body) : Bytes{});
+            return response(reply.status, reply.body, missing);
+        }
+        URL_COMPONENTS url{sizeof(url)};
+        url.dwHostNameLength = url.dwUrlPathLength = url.dwExtraInfoLength = (DWORD)-1;
+        if (!WinHttpCrackUrl(config.server.c_str(), 0, 0, &url)) throw std::runtime_error("Invalid server URL.");
+        std::wstring host(url.lpszHostName, url.dwHostNameLength);
+        HttpHandle session{WinHttpOpen(L"KSwitcher Sync/1", WINHTTP_ACCESS_TYPE_AUTOMATIC_PROXY,
+            WINHTTP_NO_PROXY_NAME, WINHTTP_NO_PROXY_BYPASS, 0)};
+        if (!session.h || !WinHttpSetTimeouts(session.h, 5000, 5000, 5000, 5000))
+            throw std::runtime_error("Cannot initialize sync connection.");
+        HttpHandle connection{WinHttpConnect(session.h, host.c_str(), url.nPort, 0)};
+        HttpHandle req{connection.h ? WinHttpOpenRequest(connection.h, method, path.c_str(), nullptr,
+            WINHTTP_NO_REFERER, WINHTTP_DEFAULT_ACCEPT_TYPES, WINHTTP_FLAG_SECURE) : nullptr};
+        DWORD redirects = WINHTTP_OPTION_REDIRECT_POLICY_NEVER;
+        if (!req.h || !WinHttpSetOption(req.h, WINHTTP_OPTION_REDIRECT_POLICY, &redirects, sizeof(redirects)))
+            throw std::runtime_error("Cannot initialize sync request.");
+        std::wstring headers = L"Content-Type: application/json\r\n";
+        if (!token.empty()) headers += L"X-Vault-Token: " + token + L"\r\n";
+        std::string payload = body ? body->dump() : "";
+        bool sent = WinHttpSendRequest(req.h, headers.c_str(), (DWORD)-1,
+            payload.empty() ? WINHTTP_NO_REQUEST_DATA : payload.data(), (DWORD)payload.size(), (DWORD)payload.size(), 0);
+        if (!payload.empty()) SecureZeroMemory(payload.data(), payload.size());
+        if (!sent || !WinHttpReceiveResponse(req.h, nullptr))
+            throw std::runtime_error("OpenBao connection failed. Check network, HTTPS certificate and server address.");
+        DWORD status{}, length = sizeof(status);
+        if (!WinHttpQueryHeaders(req.h, WINHTTP_QUERY_STATUS_CODE | WINHTTP_QUERY_FLAG_NUMBER,
+            WINHTTP_HEADER_NAME_BY_INDEX, &status, &length, WINHTTP_NO_HEADER_INDEX))
+            throw std::runtime_error("Cannot read OpenBao response.");
+        Bytes result;
+        ULONGLONG deadline = GetTickCount64() + 15000;
+        for (;;)
+        {
+            unsigned char chunk[8192]; DWORD received{};
+            if (GetTickCount64() > deadline || !WinHttpReadData(req.h, chunk, sizeof(chunk), &received))
+                throw std::runtime_error("OpenBao response timed out.");
+            if (!received) break;
+            if (result.size() + received > Limit) throw std::runtime_error("OpenBao response is too large.");
+            result.insert(result.end(), chunk, chunk + received);
+        }
+        return response(status, result, missing);
+    }
+  public:
+    explicit OpenBao(const SyncConfig &c, SyncTransport t) : config(c), transport(std::move(t))
+    {
+        validateSyncConfig(c);
+        PCREDENTIALW credential{};
+        if (!CredReadW(credentialName(c).c_str(), CRED_TYPE_GENERIC, 0, &credential))
+            throw std::runtime_error("Sign in: no saved password for this server and user.");
+        std::string password(reinterpret_cast<char *>(credential->CredentialBlob), credential->CredentialBlobSize);
+        SecureZeroMemory(credential->CredentialBlob, credential->CredentialBlobSize);
+        CredFree(credential);
+        Json login{{"password", password}};
+        SecureZeroMemory(password.data(), password.size());
+        Json response;
+        try { response = request(L"POST", L"/v1/auth/" + c.authMount + L"/login/" + c.username, &login); }
+        catch (...) { auto &p = login["password"].get_ref<std::string &>(); SecureZeroMemory(p.data(), p.size()); throw; }
+        auto &p = login["password"].get_ref<std::string &>(); SecureZeroMemory(p.data(), p.size());
+        token = wide(response.at("auth").at("client_token").get<std::string>());
+        if (token.empty() || token.find_first_of(L"\r\n") != token.npos)
+            throw std::runtime_error("Invalid OpenBao authentication response.");
+    }
+    ~OpenBao() override
+    {
+        if (token.empty()) return;
+        // Sessions are scoped to a sync attempt; do not accumulate login tokens.
+        try { request(L"POST", L"/v1/auth/token/revoke-self"); } catch (...) {}
+        SecureZeroMemory(token.data(), token.size() * sizeof(wchar_t));
+    }
+    SyncDocument read() override
+    {
+        auto j = request(L"GET", L"/v1/" + config.mount + L"/data/" + config.path, nullptr, true);
+        if (j.is_null()) return {};
+        const auto &data = j.at("data");
+        if (!data.at("metadata").value("deletion_time", std::string()).empty() ||
+            data.at("metadata").value("destroyed", false))
+            throw std::runtime_error("Remote profile is deleted or destroyed.");
+        auto payload = data.at("data");
+        if (payload.value("syncSchema", 0) != 1 && payload.value("syncSchema", 0) != 2) throw std::runtime_error("Unsupported remote sync format.");
+        return {data.at("metadata").at("version").get<uint64_t>(), bytes(payload.at("settings"))};
+    }
+    uint64_t write(const Bytes &settings, uint64_t revision) override
+    {
+        Json body{{"options", {{"cas", revision}}}, {"data", {{"syncSchema", 2}, {"settings", parse(settings)}}}};
+        auto response = request(L"POST", L"/v1/" + config.mount + L"/data/" + config.path, &body);
+        return response.at("data").at("version").get<uint64_t>();
+    }
+};
+}
+bool syncVisible(const std::filesystem::path &root) { return std::filesystem::exists(root / L"sync.json"); }
+SyncConfig loadSyncConfig(const std::filesystem::path &root)
+{
+    SyncConfig c;
+    if (!syncVisible(root)) return c;
+    auto j = parse(readFile(root / L"sync.json", 16384));
+    c.enabled = j.value("enabled", false);
+    c.keepLocalLayouts = j.value("keepLocalLayouts", false);
+    c.provider = wide(j.value("provider", "openbao"));
+    c.server = wide(j.value("server", ""));
+    c.mount = wide(j.value("mount", "kswitcher"));
+    c.path = wide(j.value("path", "personal/settings"));
+    c.authMount = wide(j.value("authMount", "userpass"));
+    c.username = wide(j.value("username", ""));
+    return c;
+}
+void validateSyncConfig(const SyncConfig &c)
+{
+    if (c.provider != L"openbao") throw std::runtime_error("Unsupported sync provider.");
+    URL_COMPONENTS url{sizeof(url)};
+    url.dwHostNameLength = url.dwUrlPathLength = url.dwExtraInfoLength = url.dwUserNameLength = url.dwPasswordLength = (DWORD)-1;
+    if (c.server.size() > 1024 || !WinHttpCrackUrl(c.server.c_str(), 0, 0, &url) ||
+        url.nScheme != INTERNET_SCHEME_HTTPS || !url.dwHostNameLength || url.dwUserNameLength ||
+        url.dwPasswordLength || url.dwExtraInfoLength ||
+        (url.dwUrlPathLength && std::wstring(url.lpszUrlPath, url.dwUrlPathLength) != L"/"))
+        throw std::runtime_error("Server must be an HTTPS origin, for example https://bao.example.com (no path or credentials).");
+    bool userValid = !c.username.empty() && c.username.size() <= 256 && c.username != L"." && c.username != L".." &&
+        c.username.find_first_not_of(L"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_-.@") == c.username.npos;
+    if (!safePath(c.mount) || !safePath(c.path) || !safePath(c.authMount) || !userValid)
+        throw std::runtime_error("Use letters, numbers, underscores and hyphens in paths and login; / is allowed only in paths.");
+    if (credentialName(c).size() > CRED_MAX_GENERIC_TARGET_NAME_LENGTH)
+        throw std::runtime_error("Sync connection name is too long.");
+}
+void saveSyncConfig(const std::filesystem::path &root, const SyncConfig &c)
+{
+    if (c.enabled) validateSyncConfig(c);
+    atomicWrite(root / L"sync.json", bytes(configJson(c)));
+}
+void saveSyncPassword(const SyncConfig &c, const std::wstring &password)
+{
+    validateSyncConfig(c);
+    auto secret = utf8(password);
+    if (secret.empty() || secret.size() > CRED_MAX_CREDENTIAL_BLOB_SIZE) throw std::runtime_error("Password is empty or too long.");
+    auto target = credentialName(c);
+    CREDENTIALW credential{}; credential.Type = CRED_TYPE_GENERIC; credential.TargetName = target.data();
+    credential.UserName = const_cast<wchar_t *>(c.username.c_str());
+    credential.CredentialBlob = reinterpret_cast<BYTE *>(secret.data());
+    credential.CredentialBlobSize = (DWORD)secret.size(); credential.Persist = CRED_PERSIST_LOCAL_MACHINE;
+    bool ok = CredWriteW(&credential, 0) != 0;
+    SecureZeroMemory(secret.data(), secret.size());
+    if (!ok) throw std::runtime_error("Cannot save password in Windows Credential Manager.");
+}
+void forgetSyncPassword(const SyncConfig &c)
+{
+    if (!CredDeleteW(credentialName(c).c_str(), CRED_TYPE_GENERIC, 0) && GetLastError() != ERROR_NOT_FOUND)
+        throw std::runtime_error("Cannot remove saved sync password.");
+}
+std::unique_ptr<SyncProvider> makeSyncProvider(const SyncConfig &c, SyncTransport transport)
+{
+    return std::make_unique<OpenBao>(c, std::move(transport));
+}
+namespace { Json canonicalProfile(Json); }
+Bytes sharedSyncSettings(const Settings &s)
+{
+    auto j = parse(encodeSettings(s));
+    // Windows may enumerate the same installed layouts in a different order on
+    // another PC. Binding order is not user intent (unlike the layout cycle).
+    auto &bindings = j["layoutHotkeys"];
+    std::sort(bindings.begin(), bindings.end(), [](const Json &a, const Json &b) {
+        return a.at("layoutId").get<std::string>() < b.at("layoutId").get<std::string>();
+    });
+    for (auto key : {"startWithSystem", "autostartAsAdministrator", "tesseractPath", "useTesseract",
+        "historyEnabled", "maxItems", "maxTotalMegabytes", "maxImageMegabytes", "writeLog", "preventScreenLock"}) j.erase(key);
+    return bytes(canonicalProfile(j));
+}
+Settings restoreSyncSettings(const Bytes &shared, const Settings &local, const std::vector<Layout> &layouts, bool keepLocalLayouts)
+{
+    auto j = parse(shared), original = parse(encodeSettings(local));
+    if (!j.contains("snippetTombstones")) j["snippetTombstones"] = Json::array();
+    if (!j.contains("autoCorrectReplace")) j["autoCorrectReplace"] = false;
+    if (!j.contains("autoCorrectTypos")) j["autoCorrectTypos"] = false;
+    if (!j.contains("autoCorrectReplacements")) j["autoCorrectReplacements"] = Json::object();
+    auto allowed = parse(sharedSyncSettings(local));
+    if (!j.is_object() || j.value("format", "") != "kswitcher-settings" || j.value("schemaVersion", 0) != 1)
+        throw std::runtime_error("Unsupported synchronized settings format.");
+    for (auto it = j.begin(); it != j.end(); ++it)
+        if (!allowed.contains(it.key())) throw std::runtime_error("Remote profile contains unsupported or local-only fields.");
+    if (j.size() != allowed.size()) throw std::runtime_error("Remote profile is incomplete.");
+    std::set<std::string> installed;
+    for (const auto &layout : layouts) installed.insert(utf8(layout.id));
+    std::set<std::string> missing;
+    for (const auto &id : j.at("layouts"))
+        if (!installed.contains(id.get<std::string>())) missing.insert(id.get<std::string>());
+    for (const auto &key : j.at("layoutHotkeys"))
+        if (!installed.contains(key.at("layoutId").get<std::string>())) missing.insert(key.at("layoutId").get<std::string>());
+    if (!keepLocalLayouts && !missing.empty())
+    {
+        std::wstring message = L"Missing keyboard layouts on this PC: ";
+        for (const auto &id : missing)
+        {
+            auto code = id.starts_with("win:") ? id.substr(4) : id;
+            wchar_t language[128]{};
+            if (code.size() == 8 && code.find_first_not_of("0123456789abcdefABCDEF") == code.npos)
+                GetLocaleInfoW(MAKELCID(LOWORD(std::stoul(code, nullptr, 16)), SORT_DEFAULT), LOCALE_SENGLISHLANGUAGENAME,
+                               language, 128);
+            if (message.back() != L' ') message += L"; ";
+            message += (language[0] ? std::wstring(language) : L"Unknown layout") + L" [" + wide(id) + L"]";
+        }
+        message += L". Install these exact layouts, or enable 'Keep this PC's layouts' below and sync other settings.";
+        throw std::runtime_error(utf8(message));
+    }
+    if (keepLocalLayouts)
+        for (auto key : {"layouts", "layoutHotkeys"}) j[key] = original.at(key);
+    original.update(j);
+    return decodeSettings(bytes(original), layouts);
+}
+#include "sync_merge.inl"
+SyncResult synchronize(SyncProvider &provider, const Bytes &base, const Bytes &local, SyncAction action,
+    const std::function<void(const Bytes &)> &validate, const std::vector<SyncChoice> &choices, bool keepLocalLayouts)
+{
+    if (local.size() > Limit) throw std::runtime_error("Settings exceed the sync size limit.");
+    if (validate) validate(local);
+    auto remote = provider.read();
+    if (!remote.revision)
+    {
+        if (action != SyncAction::Upload) throw std::runtime_error("No remote profile. Choose Upload local to create it.");
+        return {true, local, provider.write(local, 0), L"Uploaded new profile."};
+    }
+    if (validate && action != SyncAction::Upload) validate(remote.settings);
+    auto mergeLocal = local, mergeBase = base;
+    if (keepLocalLayouts)
+    {
+        // Never upload a locally filtered projection over another PC's layout setup.
+        const auto remoteJson = parse(remote.settings);
+        auto preserve = [&](const Bytes &profile)
+        {
+            auto j = parse(profile);
+            for (auto key : {"layouts", "layoutHotkeys"}) j[key] = remoteJson.at(key);
+            return bytes(j);
+        };
+        mergeLocal = preserve(local);
+        if (!base.empty()) mergeBase = preserve(base);
+    }
+    SyncMerge merged;
+    if (action == SyncAction::Automatic) merged = mergeSyncProfile(mergeBase, mergeLocal, remote.settings, choices);
+    else
+    {
+        auto selected = bytes(normalizeProfile(parse(action == SyncAction::Download ? remote.settings : mergeLocal)));
+        merged = {selected, selected, selected, {}};
+    }
+    if (validate) { validate(merged.local); validate(merged.remote); }
+    auto revision = remote.revision;
+    if (parse(merged.remote) != parse(remote.settings) && action != SyncAction::Download) revision = provider.write(merged.remote, revision);
+    return {true, merged.local, revision,
+        merged.conflicts.empty() ? L"Synchronized. Server version " + std::to_wstring(revision) + L"." :
+            L"Other changes synchronized. Resolve " + std::to_wstring(merged.conflicts.size()) + L" conflicting setting(s).",
+        merged.base, merged.conflicts};
+}
+Bytes encodeSyncConflicts(const std::vector<SyncConflict> &conflicts)
+{
+    Json j = Json::array();
+    for (const auto &c : conflicts) j.push_back({{"key", c.key}, {"label", utf8(c.label)}, {"local", parse(c.local)}, {"remote", parse(c.remote)}});
+    return bytes(j);
+}
+std::vector<SyncConflict> decodeSyncConflicts(const Bytes &data)
+{
+    std::vector<SyncConflict> result;
+    for (const auto &c : parse(data)) result.push_back({c.at("key"), wide(c.at("label").get<std::string>()), bytes(c.at("local")), bytes(c.at("remote"))});
+    return result;
+}
+Bytes encodeSyncChoices(const std::vector<SyncChoice> &choices)
+{
+    Json j = Json::array();
+    for (const auto &c : choices) j.push_back({{"conflict", parse(encodeSyncConflicts({c.conflict})).at(0)}, {"useLocal", c.useLocal}});
+    return bytes(j);
+}
+std::vector<SyncChoice> decodeSyncChoices(const Bytes &data)
+{
+    auto j = parse(data);
+    if (!j.is_array() || j.size() > 10000) throw std::runtime_error("Invalid conflict choices.");
+    std::vector<SyncChoice> result;
+    for (const auto &c : j) result.push_back({decodeSyncConflicts(bytes(Json::array({c.at("conflict")}))).at(0), c.at("useLocal").get<bool>()});
+    return result;
+}
+std::wstring syncValueText(const Bytes &data)
+{
+    auto j = parse(data);
+    if (j.is_null()) return L"(not present)";
+    if (tombstone(j)) return L"(deleted)";
+    return wide(j.is_string() ? j.get<std::string>() : j.dump(2));
+}
+Bytes loadSyncBase(const std::filesystem::path &root, const SyncConfig &c)
+{
+    auto path = root / L"sync-base.bin";
+    if (!std::filesystem::exists(path)) return {};
+    auto j = parse(unprotect(readFile(path, Limit + 65536)));
+    auto connection = j.at("connection");
+    if (!connection.contains("keepLocalLayouts")) connection["keepLocalLayouts"] = false;
+    return connection == configJson(c) ? bytes(j.at("settings")) : Bytes{};
+}
+void saveSyncBase(const std::filesystem::path &root, const SyncConfig &c, const Bytes &base)
+{
+    atomicWrite(root / L"sync-base.bin", protect(bytes({{"connection", configJson(c)}, {"settings", parse(base)}})));
+}
+}
@@ -0,0 +1,72 @@
+#pragma once
+#include "storage.h"
+#include <memory>
+
+namespace ks
+{
+struct SyncConfig
+{
+    bool enabled{};
+    bool keepLocalLayouts{};
+    std::wstring provider = L"openbao", server, mount = L"kswitcher",
+        path = L"personal/settings", authMount = L"userpass", username;
+    bool operator==(const SyncConfig &) const = default;
+};
+bool syncVisible(const std::filesystem::path &);
+SyncConfig loadSyncConfig(const std::filesystem::path &);
+void saveSyncConfig(const std::filesystem::path &, const SyncConfig &);
+void validateSyncConfig(const SyncConfig &);
+void saveSyncPassword(const SyncConfig &, const std::wstring &);
+void forgetSyncPassword(const SyncConfig &);
+struct SyncDocument { uint64_t revision{}; Bytes settings; };
+class SyncProvider
+{
+  public:
+    virtual ~SyncProvider() = default;
+    virtual SyncDocument read() = 0;
+    virtual uint64_t write(const Bytes &, uint64_t expectedRevision) = 0;
+};
+struct SyncHttpResponse { unsigned status{}; Bytes body; };
+using SyncTransport = std::function<SyncHttpResponse(const std::wstring &method, const std::wstring &path,
+    const std::wstring &token, const Bytes &body)>;
+// An injectable transport permits protocol regression tests without a live vault.
+std::unique_ptr<SyncProvider> makeSyncProvider(const SyncConfig &, SyncTransport transport = {});
+inline constexpr ULONGLONG SyncIntervalMs = 10 * 60 * 1000;
+struct SyncConflict
+{
+    std::string key;
+    std::wstring label;
+    Bytes local, remote;
+};
+struct SyncChoice { SyncConflict conflict; bool useLocal{}; };
+Bytes encodeSyncConflicts(const std::vector<SyncConflict> &);
+std::vector<SyncConflict> decodeSyncConflicts(const Bytes &);
+Bytes encodeSyncChoices(const std::vector<SyncChoice> &);
+std::vector<SyncChoice> decodeSyncChoices(const Bytes &);
+std::wstring syncValueText(const Bytes &);
+struct SyncMerge
+{
+    Bytes local, remote, base;
+    std::vector<SyncConflict> conflicts;
+};
+SyncMerge mergeSyncProfile(const Bytes &base, const Bytes &local, const Bytes &remote,
+    const std::vector<SyncChoice> &choices = {});
+Bytes mergeSyncSettings(const Bytes &base, const Bytes &local, const Bytes &remote);
+Bytes sharedSyncSettings(const Settings &);
+Settings restoreSyncSettings(const Bytes &, const Settings &, const std::vector<Layout> &, bool keepLocalLayouts = false);
+enum class SyncAction { Automatic, Download, Upload };
+struct SyncResult
+{
+    bool success{};
+    Bytes settings;
+    uint64_t revision{};
+    std::wstring status;
+    Bytes base;
+    std::vector<SyncConflict> conflicts;
+};
+SyncResult synchronize(SyncProvider &, const Bytes &base, const Bytes &local, SyncAction,
+    const std::function<void(const Bytes &)> &validate = {}, const std::vector<SyncChoice> &choices = {},
+    bool keepLocalLayouts = false);
+Bytes loadSyncBase(const std::filesystem::path &, const SyncConfig &);
+void saveSyncBase(const std::filesystem::path &, const SyncConfig &, const Bytes &);
+}
@@ -0,0 +1,201 @@
+// Three-way merge operates on individual values; unresolved values retain their
+// respective local/remote versions and their old common ancestor.
+namespace
+{
+Json normalizeProfile(Json j)
+{
+    if (!j.contains("autoCorrectReplace")) j["autoCorrectReplace"] = false;
+    if (!j.contains("autoCorrectTypos")) j["autoCorrectTypos"] = false;
+    if (!j.contains("autoCorrectReplacements")) j["autoCorrectReplacements"] = Json::object();
+    if (!j.contains("snippetTombstones")) j["snippetTombstones"] = Json::array();
+    for (auto &sn : j.at("snippets"))
+        if (!sn.contains("id")) sn["id"] = utf8(snippetId({wide(sn.at("trigger").get<std::string>()), L""}));
+    return j;
+}
+Json treeProfile(const Json &source)
+{
+    auto j = normalizeProfile(source);
+    Json items = Json::object();
+    for (const auto &sn : j.at("snippets"))
+    {
+        auto id = sn.at("id").get<std::string>();
+        if (items.contains(id)) throw std::runtime_error("Duplicate snippet ID.");
+        items[id] = sn;
+    }
+    for (const auto &id : j.at("snippetTombstones"))
+    {
+        auto key = id.get<std::string>();
+        if (items.contains(key)) throw std::runtime_error("Duplicate or deleted snippet ID.");
+        items[key] = {{"$deleted", true}};
+    }
+    j["snippets"] = items;
+    j.erase("snippetTombstones");
+    items = Json::object();
+    for (const auto &binding : j.at("layoutHotkeys")) items[binding.at("layoutId").get<std::string>()] = binding.at("hotkey");
+    j["layoutHotkeys"] = items;
+    for (auto key : {"excludedApps", "autoCorrectNever", "autoCorrectExcludedApps"})
+    {
+        items = Json::object();
+        for (const auto &item : j.at(key)) items[item.get<std::string>()] = true;
+        j[key] = items;
+    }
+    for (auto &language : j.at("autoCorrectWords").items())
+    {
+        items = Json::object();
+        for (const auto &word : language.value()) items[word.get<std::string>()] = true;
+        language.value() = items;
+    }
+    return j;
+}
+Json flatProfile(Json j)
+{
+    auto &replacements = j["autoCorrectReplacements"];
+    for (auto it = replacements.begin(); it != replacements.end();)
+        if (it.value().is_null()) it = replacements.erase(it);
+        else ++it;
+    Json snippets = Json::array(), deleted = Json::array();
+    for (const auto &[id, item] : j.at("snippets").items())
+    {
+        if (item.is_null()) continue;
+        if (item.value("$deleted", false)) deleted.push_back(id);
+        else snippets.push_back(item);
+    }
+    j["snippets"] = snippets; j["snippetTombstones"] = deleted;
+    Json bindings = Json::array();
+    for (const auto &[id, hotkey] : j.at("layoutHotkeys").items())
+        if (!hotkey.is_null()) bindings.push_back({{"layoutId", id}, {"hotkey", hotkey}});
+    j["layoutHotkeys"] = bindings;
+    for (auto key : {"excludedApps", "autoCorrectNever", "autoCorrectExcludedApps"})
+    {
+        Json list = Json::array();
+        for (const auto &[item, present] : j.at(key).items()) if (present == true) list.push_back(item);
+        j[key] = list;
+    }
+    for (auto &language : j.at("autoCorrectWords").items())
+    {
+        Json list = Json::array();
+        if (language.value().is_object())
+            for (const auto &[word, present] : language.value().items()) if (present == true) list.push_back(word);
+        language.value() = list;
+    }
+    return j;
+}
+std::string pointerKey(const std::string &s)
+{
+    std::string out;
+    for (char c : s) out += c == '~' ? "~0" : c == '/' ? "~1" : std::string(1, c);
+    return out;
+}
+Json canonicalProfile(Json j) { return flatProfile(treeProfile(j)); }
+std::wstring fieldLabel(const std::string &key)
+{
+    static const std::map<std::string, std::wstring> labels{
+        {"toggleHotkey", L"Next layout shortcut"}, {"caseHotkey", L"Change case shortcut"},
+        {"translitHotkey", L"Transliteration shortcut"}, {"undoHotkey", L"Undo shortcut"},
+        {"clipboardHotkey", L"Clipboard shortcut"}, {"screenshotHotkey", L"Screenshot shortcut"},
+        {"layouts", L"Layout cycle order"}, {"layoutHotkeys", L"Layout shortcuts"},
+        {"convertLastWord", L"Convert recent word"}, {"switchSystemLayout", L"Switch system layout"},
+        {"autoCorrectMinLength", L"Minimum word length"}, {"autoCorrectMaxRank", L"Maximum word rank"},
+        {"autoCorrectLayout", L"Automatic layout correction"}, {"autoCorrectLanguages", L"Dictionary languages"},
+        {"autoCorrectReplace", L"Custom automatic replacements"}, {"autoCorrectTypos", L"Dictionary typo correction"},
+        {"autoCorrectReplacements", L"Replacement pairs"},
+        {"autoCorrectPrefixChars", L"Punctuation before words"}, {"autoCorrectSuffixChars", L"Punctuation after words"},
+        {"screenshotAutoOpenEditor", L"Open screenshot editor"}, {"tesseractLanguages", L"OCR languages"},
+        {"trigger", L"Trigger"}, {"text", L"Text"}};
+    auto it = labels.find(key); return it == labels.end() ? wide(key) : it->second;
+}
+struct MergeNode { Json local, remote, base; };
+bool tombstone(const Json &j) { return j.is_object() && j.value("$deleted", false); }
+MergeNode mergeNode(const Json &b, const Json &l, const Json &r, const std::string &path,
+    const std::wstring &label, const std::vector<SyncChoice> &choices, std::vector<SyncConflict> &conflicts,
+    const std::set<std::string> &forced)
+{
+    if (l == r) return {l, l, l};
+    for (const auto &choice : choices)
+        if (choice.conflict.key == path && parse(choice.conflict.local) == l && parse(choice.conflict.remote) == r)
+        {
+            auto selected = choice.useLocal ? l : r;
+            if (selected.is_null() && path.starts_with("/snippets/") && path.find('/', 10) == std::string::npos)
+                selected = {{"$deleted", true}};
+            return {selected, selected, selected};
+        }
+    if (forced.contains(path))
+    {
+        conflicts.push_back({path, label + L" (duplicate trigger or shortcut)", bytes(l), bytes(r)});
+        return {l, r, b};
+    }
+    bool forcedChild = std::any_of(forced.begin(), forced.end(), [&](const std::string &key) { return key.starts_with(path + "/"); });
+    if (!forcedChild && l == b) return {r, r, r};
+    if (!forcedChild && r == b) return {l, l, l};
+    if (l.is_object() && r.is_object() && (b.is_object() || b.is_null()) && !tombstone(l) && !tombstone(r) && !tombstone(b))
+    {
+        MergeNode out{Json::object(), Json::object(), Json::object()};
+        std::set<std::string> keys;
+        for (const auto *j : {&b, &l, &r}) if (j->is_object()) for (auto it = j->begin(); it != j->end(); ++it) keys.insert(it.key());
+        for (const auto &key : keys)
+        {
+            auto get = [&](const Json &j) { return j.is_object() && j.contains(key) ? j.at(key) : Json(); };
+            auto childLabel = label.empty() ? fieldLabel(key) : label + L" / " + fieldLabel(key);
+            if (path == "/snippets")
+            {
+                auto item = get(l); if (item.is_null() || tombstone(item)) item = get(r);
+                childLabel = L"Snippet: " + wide(item.is_object() ? item.value("trigger", key) : key);
+            }
+            auto child = mergeNode(get(b), get(l), get(r), path + "/" + pointerKey(key), childLabel, choices, conflicts, forced);
+            // Keep nulls in the ancestor so deletion conflicts survive restarts.
+            out.local[key] = child.local; out.remote[key] = child.remote; out.base[key] = child.base;
+        }
+        return out;
+    }
+    conflicts.push_back({path, label, bytes(l), bytes(r)});
+    return {l, r, b};
+}
+void collisionPaths(const Json &j, std::set<std::string> &paths)
+{
+    std::map<std::wstring, std::string> triggers;
+    for (const auto &[id, sn] : j.at("snippets").items())
+    {
+        if (sn.is_null() || tombstone(sn)) continue;
+        auto path = "/snippets/" + pointerKey(id);
+        auto key = lower(wide(sn.at("trigger").get<std::string>()));
+        auto [it, inserted] = triggers.emplace(key, path);
+        if (!inserted) { paths.insert(path); paths.insert(it->second); }
+    }
+    std::map<std::pair<UINT, UINT>, std::string> shortcuts;
+    auto add = [&](const Json &text, const std::string &path) {
+        if (!text.is_string()) return;
+        auto hotkey = Hotkey::parse(wide(text.get<std::string>()));
+        if (!hotkey || !hotkey->key) return;
+        auto [it, inserted] = shortcuts.emplace(std::make_pair(hotkey->modifiers, hotkey->key), path);
+        if (!inserted) { paths.insert(path); paths.insert(it->second); }
+    };
+    for (const auto *key : {"toggleHotkey", "caseHotkey", "translitHotkey", "undoHotkey", "clipboardHotkey", "screenshotHotkey"}) add(j.at(key), std::string("/") + key);
+    for (const auto &[id, key] : j.at("layoutHotkeys").items()) add(key, "/layoutHotkeys/" + pointerKey(id));
+}
+}
+SyncMerge mergeSyncProfile(const Bytes &base, const Bytes &local, const Bytes &remote, const std::vector<SyncChoice> &choices)
+{
+    auto l = treeProfile(parse(local)), r = treeProfile(parse(remote));
+    // With no common history, union independent entries; differing scalar values
+    // remain on their respective devices until the user resolves the conflict.
+    auto b = base.empty() ? Json::object() : treeProfile(parse(base));
+    SyncMerge result;
+    auto merged = mergeNode(b, l, r, "", L"", choices, result.conflicts, {});
+    std::set<std::string> collisions;
+    collisionPaths(merged.local, collisions); collisionPaths(merged.remote, collisions);
+    if (!collisions.empty())
+    {
+        result.conflicts.clear();
+        merged = mergeNode(b, l, r, "", L"", choices, result.conflicts, collisions);
+    }
+    result.local = bytes(flatProfile(merged.local));
+    result.remote = bytes(flatProfile(merged.remote));
+    result.base = bytes(flatProfile(merged.base));
+    return result;
+}
+Bytes mergeSyncSettings(const Bytes &base, const Bytes &local, const Bytes &remote)
+{
+    auto result = mergeSyncProfile(base, local, remote);
+    if (!result.conflicts.empty()) throw std::runtime_error("Conflicting setting: " + result.conflicts.front().key);
+    return result.local;
+}
@@ -83,7 +83,7 @@ void arrangeWindow(HWND w)
    {
        int id = GetDlgCtrlID(child);
        RECT next{scale(w, r.left) - layout->x,
-                  scale(w, r.top) - layout->y + (id >= 110 && id <= 114 ? extraHeight : 0)};
+                  scale(w, r.top) - layout->y + ((id >= 110 && id <= 114) || id == 116 ? extraHeight : 0)};
        next.right = next.left + scale(w, r.right - r.left) + (id == 101 || id == 102 ? extraWidth : 0);
        next.bottom = next.top + scale(w, r.bottom - r.top) + (id == 102 ? extraHeight : 0);
        if (child == layout->stretch)
@@ -468,23 +468,31 @@ struct SearchResult
    uint64_t generation;
    std::vector<Entry> items;
 };
+struct TextPreview
+{
+    std::string rtf;
+    std::wstring plain;
+};
 struct PreviewResult
 {
    uint64_t generation;
    std::wstring id;
    Pixels pixels;
-    std::string rtf;
+    TextPreview text;
 };
 struct HistoryView
 {
    App *app{};
    std::vector<Entry> items;
+    std::wstring rememberedSelection, rememberedTop;
    uint64_t generation{};
+    std::shared_ptr<std::atomic<bool>> previewActive = std::make_shared<std::atomic<bool>>(true);
    std::map<std::wstring, Pixels> thumbnails;
-    std::map<std::wstring, std::string> richTexts;
+    std::map<std::wstring, TextPreview> richTexts;
    HWND rich{};
    std::set<std::wstring> pending;
    bool scrolling{};
+    bool closed{};
 };
 bool selectedImage(HWND w, HistoryView *v)
 {
@@ -493,7 +501,7 @@ bool selectedImage(HWND w, HistoryView *v)
 }
 void updateHistoryActions(HWND w, HistoryView *v)
 {
-    SetDlgItemTextW(w,114,selectedImage(w,v)?L"Edit image":L"Open item");
+    SetDlgItemTextW(w,114,selectedImage(w,v)?L"&Edit image":L"&Open item");
 }
 std::wstring selected(HWND w, HistoryView *v)
 {
@@ -502,16 +510,20 @@ std::wstring selected(HWND w, HistoryView *v)
 }
 void search(HWND w, HistoryView *v)
 {
+    v->previewActive->store(false);
+    v->previewActive = std::make_shared<std::atomic<bool>>(true);
+    v->closed = false;
    auto q = value(w, 101);
+    const bool pinnedOnly = SendDlgItemMessageW(w, 117, BM_GETCHECK, 0, 0) == BST_CHECKED;
    auto generation = ++v->generation;
    v->pending.clear();
    auto *app = v->app;
    app->enqueueHistorySearch(
-        [w, app, q, generation]
+        [w, app, q, generation, pinnedOnly]
        {
            try
            {
-                auto result = new SearchResult{generation, app->history->search(q)};
+                auto result = new SearchResult{generation, app->history->search(q, pinnedOnly)};
                if (!PostMessageW(w, ResultsMessage, 0, (LPARAM)result))
                    delete result;
            }
@@ -529,23 +541,31 @@ void requestPreview(HWND w, HistoryView *v, const Entry &entry)
    if (v->thumbnails.contains(id) || v->richTexts.contains(id) || !v->pending.insert(id).second)
        return;
    auto generation = v->generation;
+    auto active = v->previewActive;
    auto *app = v->app;
    app->enqueue(
-        [w, app, id, generation, image]
+        [w, app, id, generation, image, active]
        {
+            if (!active->load()) return;
            auto result = new PreviewResult{generation, id, {}, {}};
            try
            {
-                auto clip = app->history->load(id);
                if (image)
-                    result->pixels = decodeImage(clip, 208, 128);
-                else
-                    result->rtf = richPreview(clip);
+                    result->pixels = app->history->thumbnail(id, [active] { return !active->load(); });
+                else {
+                    auto clip = app->history->load(id);
+                    if (!active->load()) { delete result; return; }
+                    result->text.rtf = richPreview(clip, false);
+                    if (result->text.rtf.empty()) {
+                        result->text.plain = clip.text();
+                        if (result->text.plain.size() > 4096) result->text.plain.resize(4096);
+                    }
+                }
            }
            catch (const std::exception &)
            {
            }
-            if (!PostMessageW(w, PreviewMessage, 0, (LPARAM)result))
+            if (!active->load() || !PostMessageW(w, PreviewMessage, 0, (LPARAM)result))
                delete result;
        });
 }
@@ -599,9 +619,13 @@ void drawHistoryRow(HWND w, HistoryView *v, const DRAWITEMSTRUCT &draw)
    if (!entry.image && !entry.files)
    {
        auto rich = v->richTexts.find(entry.id);
-        if (rich != v->richTexts.end() && v->rich && !rich->second.empty())
+        if (rich != v->richTexts.end() && rich->second.rtf.empty())
+            text = (entry.pinned ? L"★  " : L"") + rich->second.plain;
+        if (rich != v->richTexts.end() && !rich->second.rtf.empty() && !v->rich)
+            v->rich = createRichText(w, 105, false);
+        if (rich != v->richTexts.end() && v->rich && !rich->second.rtf.empty())
        {
-            setRichText(v->rich, rich->second);
+            setRichText(v->rich, rich->second.rtf);
            CHARFORMAT2W format{};
            format.cbSize = sizeof(format);
            format.dwMask = CFM_COLOR;
@@ -716,6 +740,12 @@ LRESULT CALLBACK historyProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
        case WM_COMMAND:
        {
            int id = LOWORD(wp);
+            if (id == 117 && HIWORD(wp) == BN_CLICKED)
+            {
+                KillTimer(w, 1);
+                search(w, v);
+                return 0;
+            }
            if (id == 101 && HIWORD(wp) == EN_CHANGE)
            {
                // Reject an older result even during the debounce interval.
@@ -730,6 +760,13 @@ LRESULT CALLBACK historyProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
            }
            if (id == 102 && HIWORD(wp) == LBN_DBLCLK)
                id = 110;
+            if (id == 116)
+            {
+                if (MessageBoxW(w, L"Delete all clipboard history, including pinned items? This also deletes items hidden by the current search.",
+                                L"Clear history", MB_YESNO | MB_ICONWARNING | MB_DEFBUTTON2) == IDYES)
+                    v->app->clearHistory();
+                return 0;
+            }
            auto entry = selected(w, v);
            if (id == 110 || id == 111)
            {
@@ -741,7 +778,10 @@ LRESULT CALLBACK historyProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
            {
                if (!entry.empty())
                {
-                    if (id == 112)
+                    if (v->app->historyService) {
+                        v->app->remoteHistory(id == 112 ? "pin" : "remove", entry);
+                        v->app->history->reload();
+                    } else if (id == 112)
                        v->app->history->pin(entry);
                    else
                        v->app->history->remove(entry);
@@ -763,6 +803,7 @@ LRESULT CALLBACK historyProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
        }
        case WM_TIMER:
            KillTimer(w, 1);
+            if (v->closed) return 0;
            search(w, v);
            return 0;
        case ResultsMessage:
@@ -771,8 +812,10 @@ LRESULT CALLBACK historyProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
            if (result->generation != v->generation)
                return 0;
            auto old = selected(w, v);
+            if (old.empty()) old = v->rememberedSelection;
            int top=(int)SendDlgItemMessageW(w,102,LB_GETTOPINDEX,0,0);
            auto topId=top>=0 && top<(int)v->items.size()?v->items[top].id:L"";
+            if (topId.empty()) topId = v->rememberedTop;
            v->items = std::move(result->items);
            SendDlgItemMessageW(w, 102, WM_SETREDRAW, FALSE, 0);
            SendDlgItemMessageW(w, 102, LB_RESETCONTENT, 0, 0);
@@ -812,12 +855,14 @@ LRESULT CALLBACK historyProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
                visible.insert(v->items[i].id);
                if(v->items[i].id==result->id) { changed=intersection; repaint=true; }
            }
-            if (!result->rtf.empty())
-                v->richTexts[result->id] = std::move(result->rtf);
+            if (!result->text.rtf.empty() || !result->text.plain.empty())
+                v->richTexts[result->id] = std::move(result->text);
            else
                v->thumbnails[result->id] = std::move(result->pixels);
-            trimHistoryPreviews(v->thumbnails,visible);
-            trimHistoryPreviews(v->richTexts,visible);
+            trimHistoryPreviews(v->thumbnails,visible,32,HistoryThumbnailBudget,
+                                [](const Pixels &p) { return p.bgra.capacity(); });
+            trimHistoryPreviews(v->richTexts,visible,32,HistoryRichTextBudget,
+                                [](const TextPreview &s) { return s.rtf.capacity() + s.plain.capacity() * sizeof(wchar_t); });
            if(repaint) InvalidateRect(list,&changed,FALSE);
            return 0;
        }
@@ -854,12 +899,13 @@ LRESULT CALLBACK historyProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
                p={row.left,row.top}; ClientToScreen(list,&p);
            }
            HMENU menu = CreatePopupMenu();
-            AppendMenuW(menu, MF_STRING, 110, L"Paste");
-            AppendMenuW(menu, MF_STRING, 111, L"Paste plain text");
-            AppendMenuW(menu, MF_STRING, 112, L"Pin / unpin");
-            AppendMenuW(menu, MF_STRING, 113, L"Delete");
-            AppendMenuW(menu, MF_STRING, 114, selectedImage(w,v)?L"Edit image in screenshot editor":L"Open full item");
-            AppendMenuW(menu, MF_STRING, 115, L"Copy text from image (OCR)");
+            AppendMenuW(menu, MF_STRING, 110, L"&Paste");
+            AppendMenuW(menu, MF_STRING, 111, L"Paste plain &text");
+            AppendMenuW(menu, MF_STRING, 112, L"P&in / unpin");
+            AppendMenuW(menu, MF_STRING, 113, L"&Delete");
+            AppendMenuW(menu, MF_STRING, 114, selectedImage(w,v)?L"&Edit image in screenshot editor":L"&Open full item");
+            AppendMenuW(menu, MF_STRING, 115, L"&Copy text from image (OCR)");
+            showMenuAccessKeys(menu);
            int cmd = TrackPopupMenu(menu, TPM_RETURNCMD, p.x, p.y, 0, w, nullptr);
            DestroyMenu(menu);
            if (cmd)
@@ -867,15 +913,29 @@ LRESULT CALLBACK historyProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
            return 0;
        }
        case WM_CLOSE:
+        {
+            v->rememberedSelection = selected(w, v);
+            int top = (int)SendDlgItemMessageW(w,102,LB_GETTOPINDEX,0,0);
+            v->rememberedTop = top >= 0 && top < (int)v->items.size() ? v->items[top].id : L"";
+            v->app->saveHistoryView(v->rememberedSelection, v->rememberedTop, value(w, 101),
+                                   SendDlgItemMessageW(w, 117, BM_GETCHECK, 0, 0) == BST_CHECKED);
+            KillTimer(w, 1);
+            v->closed = true;
+            v->previewActive->store(false);
+            ++v->generation; // Discard search/preview results queued before closing.
            ShowWindow(w, SW_HIDE);
+            SendDlgItemMessageW(w,102,LB_RESETCONTENT,0,0);
+            std::vector<Entry>().swap(v->items);
            v->thumbnails.clear();
            v->richTexts.clear();
-            if (v->rich)
-                SetWindowTextW(v->rich, L"");
+            if (v->rich) SetWindowTextW(v->rich, L"");
            v->pending.clear();
-            ++v->generation;
+            if (v->app->historyService && !v->app->historyEntryWindows)
+                PostMessageW(v->app->window, WM_CLOSE, 0, 0);
            return 0;
+        }
        case WM_NCDESTROY:
+            v->previewActive->store(false);
            disposeFont(w);
            v->app->historyWindow = nullptr;
            delete v;
@@ -1112,6 +1172,25 @@ LRESULT CALLBACK autoOptionsProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
            draft.autoExcluded = parseCommaList(value(w, 404));
            draft.autoPrefixChars = value(w, 408);
            draft.autoSuffixChars = value(w, 409);
+            draft.autoReplace = checked(w, 414);
+            draft.autoTypos = checked(w, 415);
+            draft.autoReplacements.clear();
+            std::wistringstream replacements(lower(value(w, 416)));
+            std::wstring line;
+            auto trim = [](std::wstring text)
+            {
+                auto first = text.find_first_not_of(L" \t\r\n");
+                return first == text.npos ? std::wstring{} : text.substr(first, text.find_last_not_of(L" \t\r\n") - first + 1);
+            };
+            while (std::getline(replacements, line))
+            {
+                if (trim(line).empty()) continue;
+                auto equals = line.find(L'=');
+                if (equals == line.npos)
+                    throw std::runtime_error("Enter one replacement per line: typo=correction");
+                if (!draft.autoReplacements.emplace(trim(line.substr(0, equals)), trim(line.substr(equals + 1))).second)
+                    throw std::runtime_error("Each replacement typo must occur only once");
+            }
            if (draft.autoLanguages.size() < 2)
                throw std::runtime_error("Select at least two languages");
            validateSettings(draft);
@@ -1123,6 +1202,9 @@ LRESULT CALLBACK autoOptionsProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
            view->settings->draft.autoMinLength = draft.autoMinLength;
            view->settings->draft.autoPrefixChars = draft.autoPrefixChars;
            view->settings->draft.autoSuffixChars = draft.autoSuffixChars;
+            view->settings->draft.autoReplace = draft.autoReplace;
+            view->settings->draft.autoTypos = draft.autoTypos;
+            view->settings->draft.autoReplacements = std::move(draft.autoReplacements);
            DestroyWindow(w);
        }
        catch (const std::exception &e)
@@ -1153,15 +1235,15 @@ LRESULT CALLBACK autoOptionsProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
 }
 void showAutoOptions(HWND parent, SettingsView *v)
 {
-    HWND w = makeWindow(*v->app, L"KSwitcher.AutoOptions", L"Automatic layout correction", autoOptionsProc,
-                        560, 680);
+    HWND w = makeWindow(*v->app, L"KSwitcher.AutoOptions", L"Automatic correction", autoOptionsProc,
+                        560, 880);
    windowLayoutState(w)->autoOptions = true;
    SetWindowLongPtrW(w, GWLP_HWNDPARENT, (LONG_PTR)parent);
    SetWindowLongPtrW(w, GWLP_USERDATA, (LONG_PTR) new AutoOptionsView{parent, v});
    label(w, L"Offline dictionaries (only layouts in your cycle are used)", 18, 16, 525);
-    checkbox(w, L"English", 401, 18, 48, 150);
-    checkbox(w, L"Ukrainian", 402, 188, 48, 150);
-    checkbox(w, L"Russian", 403, 358, 48, 150);
+    checkbox(w, L"&English", 401, 18, 48, 150);
+    checkbox(w, L"&Ukrainian", 402, 188, 48, 150);
+    checkbox(w, L"&Russian", 403, 358, 48, 150);
    for (auto &lang : v->draft.autoLanguages)
        check(w, lang == L"en" ? 401 : lang == L"uk" ? 402 : 403, true);
    label(w, L"Excluded applications (process names, comma-separated)", 18, 94, 525);
@@ -1174,7 +1256,7 @@ void showAutoOptions(HWND parent, SettingsView *v)
    for (auto [id, language] : {std::pair{411, L"en"}, {412, L"uk"}, {413, L"ru"}})
    {
        int x = 18 + (id - 411) * 178;
-        label(w, id == 411 ? L"English" : id == 412 ? L"Ukrainian" : L"Russian", x, 302, 168);
+        label(w, id == 411 ? L"En&glish" : id == 412 ? L"U&krainian" : L"Ru&ssian", x, 302, 168);
        edit(w, id, x, 328, 168, 56, ES_MULTILINE | WS_VSCROLL | ES_AUTOVSCROLL | ES_WANTRETURN);
        auto words = v->draft.autoWords.find(language);
        if (words != v->draft.autoWords.end()) value(w, id, commaList(words->second));
@@ -1192,10 +1274,20 @@ void showAutoOptions(HWND parent, SettingsView *v)
    value(w, 408, v->draft.autoPrefixChars);
    value(w, 409, v->draft.autoSuffixChars);
    label(w, L"Enter punctuation without spaces or separators. These characters are kept.", 18, 530, 525);
-    button(w, L"Open dictionary folder", 407, 18, 562, 220);
-    label(w, L"After editing files, click OK here, then Save in Settings to reload.", 18, 600, 525);
-    button(w, L"OK", IDOK, 326, 632, 100);
-    button(w, L"Cancel", IDCANCEL, 440, 632, 100);
+    checkbox(w, L"Use custom &replacements (take priority over dictionaries)", 414, 18, 562, 524);
+    check(w, 414, v->draft.autoReplace);
+    label(w, L"One pair per line: typo=correction (same language, letters only)", 18, 592, 525);
+    edit(w, 416, 18, 618, 524, 70, ES_MULTILINE | WS_VSCROLL | ES_AUTOVSCROLL | ES_WANTRETURN);
+    std::wstring pairs;
+    for (const auto &[from, to] : v->draft.autoReplacements) pairs += from + L"=" + to + L"\r\n";
+    value(w, 416, pairs);
+    checkbox(w, L"Correct spelling &typos using dictionaries (experimental)", 415, 18, 700, 524);
+    check(w, 415, v->draft.autoTypos);
+    label(w, L"Single edits, 4+ letters; ambiguous words are left unchanged.", 18, 730, 525);
+    button(w, L"Open dictionary &folder", 407, 18, 762, 220);
+    label(w, L"Click OK, then Save in Settings. Enable automatic correction there.", 18, 800, 525);
+    button(w, L"&OK", IDOK, 326, 832, 100);
+    button(w, L"&Cancel", IDCANCEL, 440, 832, 100);
    RECT initial{};
    GetWindowRect(w, &initial);
    initial.right += scale(w, 200);
@@ -1278,26 +1370,67 @@ void showOcrOptions(HWND parent, SettingsView *v)
    SetWindowLongPtrW(w, GWLP_HWNDPARENT, (LONG_PTR)parent);
    SetWindowLongPtrW(w, GWLP_USERDATA, (LONG_PTR)new OcrOptionsView{parent, v});
    label(w, L"Windows OCR is used by default. Recognition stays on this computer.", 18, 16, 600);
-    checkbox(w, L"Use optional Tesseract 5 instead of Windows OCR", 501, 18, 48, 600);
+    checkbox(w, L"&Use optional Tesseract 5 instead of Windows OCR", 501, 18, 48, 600);
    check(w, 501, v->draft.useTesseract);
    label(w, L"Tesseract executable (blank = detect installed location)", 18, 90, 600);
    edit(w, 502, 18, 118, 484);
    value(w, 502, v->draft.tesseractPath);
-    button(w, L"Browse…", 504, 514, 117, 106);
+    button(w, L"&Browse…", 504, 514, 117, 106);
    label(w, L"Languages used together (for example ukr+eng+rus)", 18, 160, 600);
    edit(w, 503, 18, 188, 602);
    value(w, 503, v->draft.tesseractLanguages);
-    button(w, L"Check installation", 505, 18, 228, 180);
+    button(w, L"Check &installation", 505, 18, 228, 180);
    control(w, L"STATIC", L"", 0, 506, 212, 232, 408, 24);
-    button(w, L"Download Tesseract…", 507, 18, 266, 180);
+    button(w, L"&Download Tesseract…", 507, 18, 266, 180);
    label(w, L"Opens the Windows installer page in your browser.", 212, 270, 408);
    label(w, L"Changing the engine or languages reprocesses saved images in the background.", 18, 314, 602);
    label(w, L"Click OK here, then Save in Settings to apply. No downloads are automatic.", 18, 344, 602);
-    button(w, L"OK", IDOK, 406, 390, 100);
-    button(w, L"Cancel", IDCANCEL, 520, 390, 100);
+    button(w, L"&OK", IDOK, 406, 390, 100);
+    button(w, L"&Cancel", IDCANCEL, 520, 390, 100);
    EnableWindow(parent, FALSE);
    showRequestedWindow(w); SetForegroundWindow(w);
 }
+#include "ui_sync.inl"
+bool settingsChanged(HWND w, SettingsView *v)
+{
+    try
+    {
+        return encodeSettings(collectSettings(w, v)) != encodeSettings(v->app->settings);
+    }
+    catch (const std::exception &)
+    {
+        // Invalid edits are unsaved changes too. Allow discarding them without
+        // requiring the user to repair the fields first.
+        return true;
+    }
+}
+void closeSettings(HWND w, SettingsView *v)
+{
+    if (settingsChanged(w, v))
+    {
+        int choice = MessageBoxW(w,
+            L"You have unsaved settings changes. Save them before closing?\n\n"
+            L"Yes: save and close.\nNo: discard changes.\nCancel: keep editing.",
+            L"KSwitcher — Unsaved settings", MB_YESNOCANCEL | MB_ICONWARNING | MB_DEFBUTTON3);
+        if (choice != IDYES && choice != IDNO)
+            return;
+        if (choice == IDYES)
+        {
+            try
+            {
+                if (v->app->busy)
+                    throw std::runtime_error("Wait for the current text operation to finish");
+                v->app->applySettings(collectSettings(w, v));
+            }
+            catch (const std::exception &e)
+            {
+                error(w, e);
+                return;
+            }
+        }
+    }
+    DestroyWindow(w);
+}
 LRESULT CALLBACK settingsProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
 {
    if (msg == WM_DPICHANGED)
@@ -1334,6 +1467,7 @@ LRESULT CALLBACK settingsProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
                return 0;
            }
            if (id == 257) { showOcrOptions(w, v); return 0; }
+            if (id == 258) { showSyncOptions(w, *v->app); return 0; }
            if (id == 230)
            {
                collectLayout(w, v);
@@ -1362,7 +1496,7 @@ LRESULT CALLBACK settingsProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
            }
            if (id == IDCANCEL)
            {
-                DestroyWindow(w);
+                closeSettings(w, v);
                return 0;
            }
            if (id == 250)
@@ -1413,7 +1547,7 @@ LRESULT CALLBACK settingsProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
            break;
        }
        case WM_CLOSE:
-            DestroyWindow(w);
+            closeSettings(w, v);
            return 0;
        case WM_NCDESTROY:
            disposeFont(w);
@@ -1455,7 +1589,10 @@ void collectSnippet(HWND w, SnippetView *v)
 {
    if (v->selection >= 0 && v->selection < (int)v->snippets.size())
    {
-        v->snippets[v->selection] = {value(w, 302), value(w, 303)};
+        auto &snippet = v->snippets[v->selection];
+        if (snippet.id.empty()) snippet.id = snippetId(snippet);
+        snippet.trigger = value(w, 302);
+        snippet.text = value(w, 303);
    }
 }
 LRESULT CALLBACK snippetProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
@@ -1492,7 +1629,7 @@ LRESULT CALLBACK snippetProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
            if (id == 310)
            {
                collectSnippet(w, v);
-                v->snippets.push_back({L";new", L""});
+                v->snippets.push_back({L";new", L"", newSnippetId()});
                v->selection = (int)v->snippets.size() - 1;
                fillSnippets(w, v);
                SetFocus(GetDlgItem(w, 302));
@@ -1558,13 +1695,19 @@ LRESULT CALLBACK snippetProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
 #ifndef KS_CONFIG_APP
 LRESULT CALLBACK entryProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
 {
+    if (msg == WM_NCCREATE)
+        SetWindowLongPtrW(w, GWLP_USERDATA, (LONG_PTR)((CREATESTRUCTW *)lp)->lpCreateParams);
    if (msg == WM_SIZE)
    {
        MoveWindow(GetDlgItem(w, 1), 10, 10, LOWORD(lp) - 20, HIWORD(lp) - 20, TRUE);
        return 0;
    }
-    if (msg == WM_NCDESTROY)
+    if (msg == WM_NCDESTROY) {
        disposeFont(w);
+        auto *app = (App *)GetWindowLongPtrW(w, GWLP_USERDATA);
+        if (app && app->historyService && app->historyEntryWindows && !--app->historyEntryWindows &&
+            !IsWindowVisible(app->historyWindow)) PostMessageW(app->window, WM_CLOSE, 0, 0);
+    }
    return DefWindowProcW(w, msg, wp, lp);
 }
 #endif
@@ -1572,6 +1715,7 @@ LRESULT CALLBACK entryProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
 #ifndef KS_CONFIG_APP
 void refreshHistory(App &app)
 {
+    if (app.isolateHistory) { app.refreshHistoryProcess(); return; }
    if (app.historyWindow)
    {
        auto *v = (HistoryView *)GetWindowLongPtrW(app.historyWindow, GWLP_USERDATA);
@@ -1580,6 +1724,7 @@ void refreshHistory(App &app)
 }
 void showHistory(App &app, bool visible)
 {
+    if (app.isolateHistory) { if (visible) app.openHistoryProcess(); return; }
    if (!app.history)
    {
        app.report(L"Clipboard history is unavailable. See the log in the data folder.");
@@ -1600,21 +1745,30 @@ void showHistory(App &app, bool visible)
        HWND w = makeWindow(app, L"KSwitcher.History", L"Clipboard history", historyProc, 760, 500);
        app.historyWindow = w;
        windowLayoutState(w)->history = true;
-        ((HistoryView *)GetWindowLongPtrW(w, GWLP_USERDATA))->rich = createRichText(w, 105, false);
-        label(w, L"Search clipboard history", 16, 12, 500);
-        edit(w, 101, 16, 38, 728);
+        auto filter = control(w, L"BUTTON", L"★ Pinned only", WS_TABSTOP | BS_AUTOCHECKBOX,
+                              117, 16, 38, 112, 25);
+        SendMessageW(filter, BM_SETCHECK, app.historyPinnedOnly ? BST_CHECKED : BST_UNCHECKED, 0);
+        label(w, L"&Search clipboard history", 136, 12, 500);
+        edit(w, 101, 136, 38, 608);
        auto list = control(w, L"LISTBOX", L"",
                            WS_TABSTOP | WS_VSCROLL | LBS_NOTIFY | LBS_NOINTEGRALHEIGHT | WS_BORDER |
                                LBS_OWNERDRAWFIXED | LBS_HASSTRINGS,
                            102, 16, 76, 728, 360);
        SendMessageW(list, LB_SETITEMHEIGHT, 0, scale(w, 88));
-        button(w, L"Paste", 110, 16, 452, 90);
-        button(w, L"Plain text", 111, 114, 452, 100);
-        button(w, L"Pin / unpin", 112, 222, 452, 110);
-        button(w, L"Delete", 113, 340, 452, 90);
-        button(w, L"Open item", 114, 438, 452, 100);
+        button(w, L"&Paste", 110, 16, 452, 90);
+        button(w, L"Plain &text", 111, 114, 452, 100);
+        button(w, L"P&in / unpin", 112, 222, 452, 110);
+        button(w, L"&Delete", 113, 340, 452, 90);
+        button(w, L"&Open item", 114, 438, 452, 100);
+        button(w, L"Clear &history…", 116, 546, 452, 150);
        SetWindowSubclass(list, historyKey, 1, (DWORD_PTR)w);
        SetWindowSubclass(GetDlgItem(w, 101), historyKey, 1, (DWORD_PTR)w);
+        if (app.historyService) {
+            auto *v = (HistoryView *)GetWindowLongPtrW(w, GWLP_USERDATA);
+            v->rememberedSelection = app.historySelection;
+            v->rememberedTop = app.historyTop;
+            SetDlgItemTextW(w, 101, app.historyQuery.c_str());
+        }
    }
    if (!visible) return;
    POINT cursor;
@@ -1651,13 +1805,13 @@ void showSettings(App &app, bool visible)
    HWND w = makeWindow(app, L"KSwitcher.Settings", L"KSwitcher settings", settingsProc, 780, 660, 0, false);
    app.settingsWindow = w;
    label(w, L"Text conversion", 18, 16);
-    checkbox(w, L"Convert recently typed text when nothing is selected", 201, 18, 43, 390);
-    checkbox(w, L"Switch Windows input layout after conversion", 202, 18, 70, 390);
-    checkbox(w, L"Record clipboard history", 203, 18, 106);
-    checkbox(w, L"Start with Windows", 204, 18, 133);
-    checkbox(w, L"Start with Windows as administrator", 206, 18, 160, 395);
-    checkbox(w, L"Keep screen awake", 205, 18, 184, 210);
-    checkbox(w, L"Write log", 208, 240, 184, 160);
+    checkbox(w, L"Con&vert recently typed text when nothing is selected", 201, 18, 43, 390);
+    checkbox(w, L"Switch Windows input &layout after conversion", 202, 18, 70, 390);
+    checkbox(w, L"Record clip&board history", 203, 18, 106);
+    checkbox(w, L"Start with &Windows", 204, 18, 133);
+    checkbox(w, L"Start with Windows as ad&ministrator", 206, 18, 160, 395);
+    checkbox(w, L"&Keep screen awake", 205, 18, 184, 210);
+    checkbox(w, L"Write lo&g", 208, 240, 184, 160);
    label(w, L"Click a shortcut and press the desired keys", 420, 16, 350);
    const wchar_t *names[] = {L"Next layout", L"Change case", L"Transliterate", L"Undo",
                              L"Clipboard history", L"Screen capture"};
@@ -1666,18 +1820,18 @@ void showSettings(App &app, bool visible)
        label(w, names[i], 420, 48 + i * 30, 115);
        hotkeyEdit(app, w, 210 + i, 540, 44 + i * 30, 220);
    }
-    checkbox(w, L"Open editor after screen capture", 209, 420, 224, 340);
-    checkbox(w, L"Automatically correct layout (experimental)", 207, 18, 210, 395);
+    checkbox(w, L"Open editor after screen capt&ure", 209, 420, 224, 340);
+    checkbox(w, L"Automatic correction (e&xperimental)", 207, 18, 210, 395);
    label(w, L"Layout cycle — top to bottom", 18, 240, 400);
    control(w, L"LISTBOX", L"", WS_TABSTOP | WS_VSCROLL | LBS_NOTIFY | LBS_NOINTEGRALHEIGHT | WS_BORDER, 220,
            18, 262, 470, 172);
-    button(w, L"Move up", 232, 504, 262, 120);
-    button(w, L"Move down", 233, 632, 262, 128);
-    checkbox(w, L"Include in cycle", 230, 504, 300, 240);
+    button(w, L"Move u&p", 232, 504, 262, 120);
+    button(w, L"Move &down", 233, 632, 262, 128);
+    checkbox(w, L"&Include in cycle", 230, 504, 300, 240);
    label(w, L"Direct layout shortcut", 504, 332, 240);
    hotkeyEdit(app, w, 231, 504, 356, 256);
    label(w, L"Backspace / Delete clears a shortcut", 504, 382, 256);
-    button(w, L"Refresh layouts", 253, 504, 408, 150);
+    button(w, L"Re&fresh layouts", 253, 504, 408, 150);
    label(w, L"History limits", 18, 444);
    label(w, L"Items", 18, 478, 50);
    edit(w, 240, 70, 474, 90);
@@ -1685,17 +1839,18 @@ void showSettings(App &app, bool visible)
    edit(w, 241, 260, 474, 90);
    label(w, L"Per item MiB", 370, 478, 100);
    edit(w, 242, 475, 474, 80);
-    button(w, L"Clear history…", 254, 580, 474, 180);
+    button(w, L"Clear &history…", 254, 580, 474, 180);
    label(w, L"Exclude applications (process names, comma-separated)", 18, 516, 700);
    edit(w, 243, 18, 544, 742);
-    button(w, L"Auto-correction options…", 255, 18, 575, 240);
-    button(w, L"View log…", 256, 278, 575, 220);
-    button(w, L"OCR options…", 257, 518, 575, 242);
-    button(w, L"Import settings…", 250, 18, 606, 145);
-    button(w, L"Export settings…", 251, 173, 606, 145);
-    button(w, L"Snippets…", 252, 328, 606, 110);
-    button(w, L"Save", IDOK, 548, 606, 100);
-    button(w, L"Cancel", IDCANCEL, 660, 606, 100);
+    button(w, L"&Auto-correction options…", 255, 18, 575, 240);
+    button(w, L"View l&og…", 256, 278, 575, 220);
+    button(w, L"OCR op&tions…", 257, 518, 575, 242);
+    button(w, L"Impo&rt settings…", 250, 18, 606, 145);
+    button(w, L"&Export settings…", 251, 173, 606, 145);
+    button(w, L"S&nippets…", 252, 328, 606, 110);
+    button(w, L"S&ync...", 258, 448, 606, 90);
+    button(w, L"&Save", IDOK, 548, 606, 100);
+    button(w, L"&Cancel", IDCANCEL, 660, 606, 100);
    fillSettings(w, (SettingsView *)GetWindowLongPtrW(w, GWLP_USERDATA));
    if (visible)
    {
@@ -1715,17 +1870,17 @@ void showSnippets(App &app)
    label(w, L"Triggers", 16, 16);
    control(w, L"LISTBOX", L"", WS_TABSTOP | WS_VSCROLL | LBS_NOTIFY | LBS_NOINTEGRALHEIGHT | WS_BORDER, 301,
            16, 44, 200, 380);
-    button(w, L"Add", 310, 16, 438, 90);
-    button(w, L"Delete", 311, 116, 438, 100);
-    label(w, L"Trigger (for example ;addr)", 236, 16, 470);
+    button(w, L"&Add", 310, 16, 438, 90);
+    button(w, L"&Delete", 311, 116, 438, 100);
+    label(w, L"&Trigger (for example ;addr)", 236, 16, 470);
    edit(w, 302, 236, 44, 488);
-    label(w, L"Replacement text", 236, 82, 480);
+    label(w, L"&Replacement text", 236, 82, 480);
    edit(w, 303, 236, 110, 488, 270, ES_MULTILINE | ES_WANTRETURN | ES_AUTOVSCROLL | WS_VSCROLL);
    control(w, L"STATIC", L"{cursor}: caret; {enter}: press Enter after insertion.\nUse {{cursor}} / {{enter}} for literal markers.", 0, 0, 236, 392, 488, 36);
-    button(w, L"Insert cursor marker", 312, 236, 430, 190);
-    button(w, L"Insert Enter marker", 313, 436, 430, 190);
-    button(w, L"Save", IDOK, 510, 478, 100);
-    button(w, L"Cancel", IDCANCEL, 624, 478, 100);
+    button(w, L"Insert cursor &marker", 312, 236, 430, 190);
+    button(w, L"Insert &Enter marker", 313, 436, 430, 190);
+    button(w, L"&Save", IDOK, 510, 478, 100);
+    button(w, L"&Cancel", IDCANCEL, 624, 478, 100);
    fillSnippets(w, (SnippetView *)GetWindowLongPtrW(w, GWLP_USERDATA));
    showRequestedWindow(w);
    SetForegroundWindow(w);
@@ -1770,6 +1925,7 @@ void showEntry(App &app, const std::wstring &id)
        }
        HWND w = makeWindow(app, L"KSwitcher.Entry", L"Clipboard item", entryProc, 720, 500,
                            WS_THICKFRAME | WS_MAXIMIZEBOX);
+        if (app.historyService) ++app.historyEntryWindows;
        auto field = edit(w, 1, 10, 10, 700, 480, ES_MULTILINE | ES_READONLY | ES_AUTOVSCROLL | WS_VSCROLL);
        SetWindowTextW(field, text.c_str());
        showRequestedWindow(w);
@@ -309,18 +309,18 @@ void showLogs(App &app)
    SendMessageW(choice, CB_ADDSTRING, 0, (LPARAM)L"Current log — kswitcher.log");
    SendMessageW(choice, CB_ADDSTRING, 0, (LPARAM)L"Previous log — kswitcher.log.1");
    SendMessageW(choice, CB_SETCURSEL, 0, 0);
-    button(w, L"Refresh", LogRefresh, 310, 14, 100);
-    button(w, L"Copy selected", LogCopy, 424, 14, 140);
-    button(w, L"Clear log", LogClear, 578, 14, 100);
+    button(w, L"&Refresh", LogRefresh, 310, 14, 100);
+    button(w, L"&Copy selected", LogCopy, 424, 14, 140);
+    button(w, L"Clear &log", LogClear, 578, 14, 100);
    control(w, L"STATIC", L"", 0, LogStatus, 16, 49, 1068, 22);
-    label(w, L"Program", 16, 78, 170);
+    label(w, L"&Program", 16, 78, 170);
    control(w, L"COMBOBOX", L"", WS_TABSTOP | CBS_DROPDOWNLIST | WS_VSCROLL, LogProgram, 16, 101, 174, 300);
-    label(w, L"Command", 206, 78, 200);
+    label(w, L"Co&mmand", 206, 78, 200);
    control(w, L"COMBOBOX", L"", WS_TABSTOP | CBS_DROPDOWNLIST | WS_VSCROLL, LogCommand, 206, 101, 204, 300);
-    label(w, L"Result", 426, 78, 300);
+    label(w, L"Res&ult", 426, 78, 300);
    control(w, L"COMBOBOX", L"", WS_TABSTOP | CBS_DROPDOWNLIST | WS_VSCROLL, LogResult, 426, 101, 310, 300);
-    checkbox(w, L"Only problems", LogProblems, 752, 102, 166);
-    button(w, L"Reset filters", LogReset, 938, 98, 146);
+    checkbox(w, L"&Only problems", LogProblems, 752, 102, 166);
+    button(w, L"Reset &filters", LogReset, 938, 98, 146);
    INITCOMMONCONTROLSEX common{sizeof(common), ICC_LISTVIEW_CLASSES};
    InitCommonControlsEx(&common);
    auto list = control(w, WC_LISTVIEWW, L"", WS_TABSTOP | WS_BORDER | LVS_REPORT | LVS_SHOWSELALWAYS,
@@ -344,7 +344,7 @@ void showLogs(App &app)
        w, L"STATIC",
        L"Click a column to sort. Select an operation for details. Ctrl+C copies selected operations.", 0, 0,
        16, 712, 860, 22);
-    button(w, L"Close", IDCANCEL, 974, 708, 110);
+    button(w, L"Clos&e", IDCANCEL, 974, 708, 110);
    auto *layout = windowLayoutState(w);
    layout->stretch = list;
    layout->details = details;
@@ -0,0 +1,149 @@
+#include "ui_sync_conflicts.inl"
+struct SyncView { HWND parent; App *app; };
+void updateSyncControls(HWND w, App &app)
+{
+    bool enabled = checked(w, 601);
+    bool savedEnabled = loadSyncConfig(app.data).enabled;
+    for (int id : {602, 603, 604, 605, 606, 607, 610, 611, 613})
+        EnableWindow(GetDlgItem(w, id), enabled);
+    EnableWindow(GetDlgItem(w, 612), enabled && savedEnabled);
+    EnableWindow(GetDlgItem(w, IDOK), enabled || savedEnabled);
+    value(w, IDOK, enabled ? L"&Save / Sign in / Sync" : L"&Save");
+    std::wstring status;
+    if (!enabled)
+        status = savedEnabled ? L"Click Save to disable synchronization." :
+              L"Synchronization is disabled. Enable it above to configure and sync.";
+    else if (!savedEnabled)
+        status = L"Configure the connection, then click Save / Sign in / Sync to enable synchronization.";
+    else
+        status = app.syncCommand();
+    if (value(w, 608) != status) value(w, 608, status);
+}
+SyncConfig syncFields(HWND w)
+{
+    SyncConfig c;
+    c.enabled = checked(w, 601);
+    c.keepLocalLayouts = checked(w, 613);
+    c.server = value(w, 602);
+    while (!c.server.empty() && c.server.back() == L'/') c.server.pop_back();
+    c.username = lower(value(w, 603)); c.mount = value(w, 605);
+    c.path = value(w, 606); c.authMount = value(w, 607);
+    return c;
+}
+LRESULT CALLBACK syncProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
+{
+    if (msg == WM_DPICHANGED) { resizeForDpi(w, wp, lp); return 0; }
+    auto *v = reinterpret_cast<SyncView *>(GetWindowLongPtrW(w, GWLP_USERDATA));
+    if (!v) return DefWindowProcW(w, msg, wp, lp);
+    try
+    {
+        if (msg == WM_TIMER)
+        {
+            updateSyncControls(w, *v->app);
+            return 0;
+        }
+        if (msg == WM_COMMAND)
+        {
+            int id = LOWORD(wp);
+            if (id == 601 && HIWORD(wp) == BN_CLICKED)
+            {
+                updateSyncControls(w, *v->app);
+                return 0;
+            }
+            if ((id == IDOK || id == 610 || id == 611 || id == 612) &&
+                !IsWindowEnabled(GetDlgItem(w, id))) return 0;
+            if (id == 612) { showSyncConflicts(w, *v->app); return 0; }
+            if (id == IDCANCEL) { DestroyWindow(w); return 0; }
+            if (id == 609)
+            {
+                auto c = loadSyncConfig(v->app->data);
+                c.enabled = false;
+                saveSyncConfig(v->app->data, c);
+                forgetSyncPassword(c);
+                check(w, 601, false);
+                value(w, 604, L"");
+                updateSyncControls(w, *v->app);
+                value(w, 608, L"Disabled. Saved password removed. An in-flight server request may still finish.");
+                KillTimer(w, 1);
+                return 0;
+            }
+            if (id == IDOK || id == 610 || id == 611)
+            {
+                if (!checked(w, 601))
+                {
+                    if (id != IDOK) return 0;
+                    auto c = loadSyncConfig(v->app->data);
+                    c.enabled = false;
+                    saveSyncConfig(v->app->data, c);
+                    value(w, 604, L"");
+                    updateSyncControls(w, *v->app);
+                    return 0;
+                }
+                if (id != IDOK && MessageBoxW(w, id == 610 ?
+                    L"Replace this PC's shared settings with the remote profile? A local backup will be saved. Unsaved edits in Settings are not included." :
+                    L"Replace the remote profile with this PC's saved settings? OpenBao retains older versions according to its retention policy. Unsaved edits are not included.",
+                    L"Resolve synchronization", MB_YESNO | MB_ICONWARNING) != IDYES) return 0;
+                auto c = syncFields(w);
+                if (c.enabled) validateSyncConfig(c);
+                auto password = value(w, 604);
+                try { if (!password.empty()) saveSyncPassword(c, password); }
+                catch (...) { SecureZeroMemory(password.data(), password.size() * sizeof(wchar_t)); throw; }
+                SecureZeroMemory(password.data(), password.size() * sizeof(wchar_t));
+                value(w, 604, L"");
+                saveSyncConfig(v->app->data, c);
+                value(w, 608, v->app->syncCommand(id == 610 ? 2 : id == 611 ? 3 : 1));
+                updateSyncControls(w, *v->app);
+                SetTimer(w, 1, 1000, nullptr);
+                return 0;
+            }
+        }
+    }
+    catch (const std::exception &e)
+    {
+        // Never display parser exceptions containing connection file contents.
+        value(w, 608, L"Unable to complete sync action. Check connection fields and saved configuration.");
+        if (dynamic_cast<const std::runtime_error *>(&e))
+            value(w, 608, wide(e.what()));
+        return 0;
+    }
+    if (msg == WM_CLOSE) { DestroyWindow(w); return 0; }
+    if (msg == WM_NCDESTROY)
+    {
+        KillTimer(w, 1);
+        EnableWindow(v->parent, TRUE); SetForegroundWindow(v->parent);
+        disposeFont(w); delete v; SetWindowLongPtrW(w, GWLP_USERDATA, 0);
+    }
+    return DefWindowProcW(w, msg, wp, lp);
+}
+void showSyncOptions(HWND parent, App &app)
+{
+    auto c = loadSyncConfig(app.data);
+    HWND w = makeWindow(app, L"KSwitcher.Sync", L"Settings synchronization - OpenBao", syncProc, 660, 672);
+    SetWindowLongPtrW(w, GWLP_HWNDPARENT, (LONG_PTR)parent);
+    SetWindowLongPtrW(w, GWLP_USERDATA, (LONG_PTR)new SyncView{parent, &app});
+    checkbox(w, L"&Enable synchronization with your OpenBao (KV v2)", 601, 18, 18, 620);
+    check(w, 601, c.enabled);
+    label(w, L"Se&rver (HTTPS)", 18, 60, 160); edit(w, 602, 190, 56, 450); value(w, 602, c.server);
+    label(w, L"User&name", 18, 100, 160); edit(w, 603, 190, 96, 450); value(w, 603, c.username);
+    label(w, L"&Password", 18, 140, 160); edit(w, 604, 190, 136, 450, 25, ES_AUTOHSCROLL | ES_PASSWORD);
+    label(w, L"Leave password blank to use the saved Windows credential.", 190, 166, 450);
+    label(w, L"KV v2 &mount", 18, 210, 160); edit(w, 605, 190, 206, 450); value(w, 605, c.mount);
+    label(w, L"Profile pa&th", 18, 250, 160); edit(w, 606, 190, 246, 450); value(w, 606, c.path);
+    label(w, L"&Login mount", 18, 290, 160); edit(w, 607, 190, 286, 450); value(w, 607, c.authMount);
+    label(w, L"Sync uses saved settings. Close and reopen Settings after downloading changes.", 18, 330, 622);
+    edit(w, 608, 18, 362, 622, 76, ES_MULTILINE | ES_READONLY | WS_VSCROLL | ES_AUTOVSCROLL);
+    value(w, 608, app.syncCommand());
+    checkbox(w, L"&Keep this PC's layouts and layout shortcuts (sync other settings)", 613, 18, 446, 622);
+    check(w, 613, c.keepLocalLayouts);
+    button(w, L"&Save / Sign in / Sync", IDOK, 18, 484, 200);
+    button(w, L"&Download remote", 610, 230, 484, 195);
+    button(w, L"&Upload local", 611, 437, 484, 203);
+    button(w, L"Resolve &individual conflicts...", 612, 18, 530, 300);
+    label(w, L"Background check: every 10 minutes", 330, 534, 310);
+    button(w, L"Disconnect / &forget password", 609, 18, 582, 290);
+    button(w, L"&Close", IDCANCEL, 540, 582, 100);
+    updateSyncControls(w, app);
+    EnableWindow(parent, FALSE);
+    SetTimer(w, 1, 1000, nullptr);
+    showRequestedWindow(w); SetForegroundWindow(w);
+}
@@ -0,0 +1,80 @@
+struct SyncConflictView
+{
+    HWND parent;
+    App *app;
+    std::vector<SyncConflict> conflicts;
+    std::map<size_t, bool> choices;
+};
+void showConflictValues(HWND w, SyncConflictView *v)
+{
+    int selected = (int)SendDlgItemMessageW(w, 620, LB_GETCURSEL, 0, 0);
+    if (selected < 0 || selected >= (int)v->conflicts.size()) return;
+    const auto &c = v->conflicts[selected];
+    value(w, 621, syncValueText(c.local)); value(w, 622, syncValueText(c.remote));
+}
+LRESULT CALLBACK syncConflictsProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
+{
+    if (msg == WM_DPICHANGED) { resizeForDpi(w, wp, lp); return 0; }
+    auto *v = reinterpret_cast<SyncConflictView *>(GetWindowLongPtrW(w, GWLP_USERDATA));
+    if (!v) return DefWindowProcW(w, msg, wp, lp);
+    try
+    {
+        if (msg == WM_COMMAND)
+        {
+            int id = LOWORD(wp);
+            if (id == 620 && HIWORD(wp) == LBN_SELCHANGE) { showConflictValues(w, v); return 0; }
+            if (id == 623 || id == 624)
+            {
+                int selected = (int)SendDlgItemMessageW(w, 620, LB_GETCURSEL, 0, 0);
+                if (selected < 0 || selected >= (int)v->conflicts.size()) return 0;
+                v->choices[selected] = id == 623;
+                auto text = v->conflicts[selected].label + (id == 623 ? L"  [This PC]" : L"  [Server]");
+                SendDlgItemMessageW(w, 620, LB_DELETESTRING, selected, 0);
+                SendDlgItemMessageW(w, 620, LB_INSERTSTRING, selected, (LPARAM)text.c_str());
+                SendDlgItemMessageW(w, 620, LB_SETCURSEL, selected, 0);
+                return 0;
+            }
+            if (id == IDOK)
+            {
+                if (v->choices.empty()) throw std::runtime_error("Select a setting and choose This PC or Server first.");
+                std::vector<SyncChoice> choices;
+                for (const auto &[index, local] : v->choices) choices.push_back({v->conflicts.at(index), local});
+                auto status = v->app->syncCommand(4, choices);
+                value(v->parent, 608, status);
+                if (status != L"Connecting to OpenBao...") throw std::runtime_error(utf8(status));
+                DestroyWindow(w); return 0;
+            }
+            if (id == IDCANCEL) { DestroyWindow(w); return 0; }
+        }
+    }
+    catch (const std::exception &e) { error(w, e); return 0; }
+    if (msg == WM_CLOSE) { DestroyWindow(w); return 0; }
+    if (msg == WM_NCDESTROY)
+    {
+        EnableWindow(v->parent, TRUE); SetForegroundWindow(v->parent);
+        disposeFont(w); delete v; SetWindowLongPtrW(w, GWLP_USERDATA, 0);
+    }
+    return DefWindowProcW(w, msg, wp, lp);
+}
+void showSyncConflicts(HWND parent, App &app)
+{
+    auto conflicts = decodeSyncConflicts(app.syncConflictData());
+    if (conflicts.empty()) { value(parent, 608, L"No pending conflicts. Run Sync to check for changes."); return; }
+    HWND w = makeWindow(app, L"KSwitcher.SyncConflicts", L"Resolve individual settings", syncConflictsProc, 800, 560);
+    SetWindowLongPtrW(w, GWLP_HWNDPARENT, (LONG_PTR)parent);
+    auto *v = new SyncConflictView{parent, &app, std::move(conflicts), {}};
+    SetWindowLongPtrW(w, GWLP_USERDATA, (LONG_PTR)v);
+    label(w, L"Choose a value for each conflicting setting. Other changes are already synchronized.", 18, 16, 760);
+    control(w, L"LISTBOX", L"", WS_TABSTOP | WS_VSCROLL | LBS_NOTIFY | WS_BORDER, 620, 18, 48, 760, 130);
+    for (const auto &c : v->conflicts) SendDlgItemMessageW(w, 620, LB_ADDSTRING, 0, (LPARAM)c.label.c_str());
+    label(w, L"This PC", 18, 190, 360); label(w, L"Server", 410, 190, 368);
+    edit(w, 621, 18, 220, 368, 180, ES_MULTILINE | ES_READONLY | ES_AUTOVSCROLL | WS_VSCROLL);
+    edit(w, 622, 410, 220, 368, 180, ES_MULTILINE | ES_READONLY | ES_AUTOVSCROLL | WS_VSCROLL);
+    button(w, L"Use this &PC for selected setting", 623, 18, 412, 368);
+    button(w, L"Use &server for selected setting", 624, 410, 412, 368);
+    label(w, L"Unselected conflicts stay pending. Changed values will be checked again before saving.", 18, 454, 760);
+    button(w, L"&Apply choices", IDOK, 526, 488, 140);
+    button(w, L"&Cancel", IDCANCEL, 678, 488, 100);
+    SendDlgItemMessageW(w, 620, LB_SETCURSEL, 0, 0); showConflictValues(w, v);
+    EnableWindow(parent, FALSE); showRequestedWindow(w); SetForegroundWindow(w);
+}
@@ -2,7 +2,7 @@
 #include "platform.h"
 namespace ks
 {
-inline constexpr wchar_t AppVersion[] = L"0.6.20";
+inline constexpr wchar_t AppVersion[] = L"0.6.43";
 inline constexpr UINT UpdateMessage = WM_APP + 7;
 inline constexpr UINT UpdateCheckIntervalMs = 6 * 60 * 60 * 1000;
 inline constexpr UINT UpdateNotificationRetryMs = 5 * 60 * 1000;
@@ -0,0 +1,108 @@
+// Run with the resident stopped. The suite restores the original clipboard.
+#include "storage.h"
+#include "ocr.h"
+#include <psapi.h>
+#include <iostream>
+#include <algorithm>
+static void require(bool ok, const char *name) {
+    if (!ok) throw std::runtime_error(name);
+    std::cout << "PASS " << name << '\n';
+}
+static HWND owner() {
+    return CreateWindowExW(0,L"STATIC",L"Snapshot test",0,0,0,0,0,HWND_MESSAGE,nullptr,nullptr,nullptr);
+}
+static void child(const std::wstring &argument) {
+    auto exe=ks::executable(), command=L"\""+exe+L"\" "+argument;
+    STARTUPINFOW startup{sizeof(startup)}; startup.dwFlags=STARTF_USESHOWWINDOW; startup.wShowWindow=SW_HIDE;
+    PROCESS_INFORMATION p{};
+    if(!CreateProcessW(exe.c_str(),command.data(),nullptr,nullptr,FALSE,CREATE_NO_WINDOW,nullptr,nullptr,&startup,&p))
+        throw std::runtime_error("start fixture process");
+    CloseHandle(p.hThread);
+    auto wait=WaitForSingleObject(p.hProcess,30000); DWORD code=1;
+    if(wait!=WAIT_OBJECT_0) {TerminateProcess(p.hProcess,1);WaitForSingleObject(p.hProcess,INFINITE);}
+    GetExitCodeProcess(p.hProcess,&code); CloseHandle(p.hProcess);
+    if(code) throw std::runtime_error("fixture process failed");
+}
+static size_t resident() {
+    ks::Bytes b(1024*1024); auto ws=reinterpret_cast<PSAPI_WORKING_SET_INFORMATION*>(b.data());
+    if(!QueryWorkingSet(GetCurrentProcess(),ws,DWORD(b.size()))) throw std::runtime_error("working set query");
+    size_t pages=0; for(size_t i=0;i<ws->NumberOfEntries;++i) if(!ws->WorkingSetInfo[i].Shared) ++pages;
+    return pages*4096;
+}
+static void verifyImage(HWND w) {
+    auto c=ks::readClipboard(w,64*1024*1024);
+    for(auto id:{CF_DIB,CF_DIBV5}) {
+        auto it=std::find_if(c.formats.begin(),c.formats.end(),[&](const auto &f){return f.id==UINT(id);});
+        require(it!=c.formats.end(),"restores image representation");
+        auto pixels=ks::decodeImage(ks::Clip{{*it}});
+        require(pixels.width==1566 && pixels.height==1068 && pixels.bgra.front()==77,"preserves image pixels");
+    }
+    require(c.text()==L"Snapshot mixed text","preserves accompanying text");
+}
+int main(int argc,char**argv) {
+    CoInitializeEx(nullptr,COINIT_MULTITHREADED);
+    HWND w=owner(); int result=0; ks::Clip original; bool saved=false;
+    try {
+        std::string mode=argc>1?argv[1]:"suite";
+        if(mode=="publish") {
+            ks::Pixels p{1566,1068,ks::Bytes(1566*1068*4,255)}; p.bgra[0]=77;
+            auto dib=ks::imageDib(p); auto v5=dib;
+            BITMAPV5HEADER h{}; h.bV5Size=sizeof(h); h.bV5Width=p.width; h.bV5Height=-p.height;
+            h.bV5Planes=1; h.bV5BitCount=32; h.bV5Compression=BI_BITFIELDS;
+            h.bV5RedMask=0xff0000; h.bV5GreenMask=0xff00; h.bV5BlueMask=0xff; h.bV5AlphaMask=0xff000000;
+            v5.id=CF_DIBV5; v5.data.resize(sizeof(h)+p.bgra.size());
+            memcpy(v5.data.data(),&h,sizeof(h)); memcpy(v5.data.data()+sizeof(h),p.bgra.data(),p.bgra.size());
+            auto clip=ks::textClip(L"Snapshot mixed text"); clip.formats.push_back(dib); clip.formats.push_back(v5);
+            ks::writeClipboard(w,clip);
+        } else if(mode=="old" || mode=="new") {
+            child(L"publish"); auto baseline=resident();
+            if(mode=="old") {
+                auto clip=ks::readClipboard(w,64*1024*1024);
+                ks::writeClipboard(w,ks::textClip(L"temporary")); ks::writeClipboard(w,clip);
+            } else {
+                ks::ClipboardSnapshot snapshot; snapshot.capture(w,GetClipboardSequenceNumber());
+                auto seq=ks::writeClipboard(w,ks::textClip(L"temporary"));
+                require(snapshot.restore(w,seq)==GetClipboardSequenceNumber(),"helper returns current sequence");
+            }
+            auto after=resident();
+            auto report="baseline="+std::to_string(baseline)+" after="+std::to_string(after)+" delta="+std::to_string(int64_t(after)-int64_t(baseline))+"\n";
+            auto path=std::filesystem::path(ks::executable()).parent_path()/(L"snapshot-memory-"+ks::wide(mode)+L".txt");
+            ks::atomicWrite(path,ks::Bytes(report.begin(),report.end()));
+            verifyImage(w); // Only after measuring: verification intentionally reads images.
+        } else {
+            original=ks::readClipboard(w,128*1024*1024); saved=true;
+            child(L"old"); child(L"new"); child(L"publish");
+            auto seq=GetClipboardSequenceNumber();
+            auto selected=ks::readClipboard(w,32*1024*1024,ks::ClipboardRead::Selection);
+            require(selected.formats.size()==1 && selected.text()==L"Snapshot mixed text","selection read excludes image data");
+            bool rejected=false;
+            try {ks::readClipboard(w,32*1024*1024,ks::ClipboardRead::WithoutImages,seq);} catch(...) {rejected=true;}
+            require(rejected,"resident rejects images before reading their data");
+            {
+                ks::ClipboardSnapshot snapshot; snapshot.capture(w,seq);
+                auto stale=ks::writeClipboard(w,ks::textClip(L"temporary"));
+                ks::writeClipboard(w,ks::textClip(L"external copy")); rejected=false;
+                try {snapshot.restore(w,stale);} catch(...) {rejected=true;}
+                require(rejected && ks::readClipboard(w).text()==L"external copy","stale image restore preserves external copy");
+            }
+            {
+                ks::ClipboardSnapshot snapshot; snapshot.capture(w,GetClipboardSequenceNumber());
+                auto temporary=ks::writeClipboard(w,ks::textClip(L"temporary"));
+                snapshot.restore(w,temporary);
+                require(ks::readClipboard(w).text()==L"external copy","text snapshot fast path restores clipboard");
+            }
+            {
+                ks::Clip empty; auto seqEmpty=ks::writeClipboard(w,empty);
+                ks::ClipboardSnapshot snapshot; snapshot.capture(w,seqEmpty);
+                snapshot.restore(w,ks::writeClipboard(w,ks::textClip(L"temporary")));
+                require(ks::readClipboard(w).formats.empty(),"empty clipboard restored");
+            }
+            auto marked=ks::textClip(L"line"); marked.formats.push_back({0,L"MSDEVLineSelect",ks::Bytes{1}});
+            ks::writeClipboard(w,marked);
+            require(ks::readClipboard(w,1024,ks::ClipboardRead::Selection).formats.size()==2,"selection reader preserves editor guard metadata");
+            std::cout<<"PASS clipboard snapshot suite\n";
+        }
+    } catch(const std::exception &e) {std::cerr<<"FAIL "<<e.what()<<'\n';result=1;}
+    if(saved) try {ks::writeClipboard(w,original);} catch(...) {result=1;}
+    DestroyWindow(w); CoUninitialize(); return result;
+}
@@ -0,0 +1,85 @@
+#include "autocorrect.h"
+#include <algorithm>
+#include <chrono>
+#include <fstream>
+#include <iostream>
+#include <psapi.h>
+#include <random>
+namespace ks {
+struct AutoCorrectorRegressionAccess {
+ static int rank(const AutoCorrector &c,const std::wstring &lang,const std::wstring &word) {
+  return c.dictionaries.at(lang)->rank(word);
+ }
+ static std::vector<int> ranks(const std::filesystem::path &path,const std::vector<std::wstring> &words) {
+  AutoCorrector::Dictionary d(path);
+  std::vector<int> values;for(const auto &word:words)values.push_back(d.rank(word));return values;
+ }
+};
+}
+int main(int argc,char **argv) {
+ try {
+  auto start=std::chrono::steady_clock::now();
+  ks::AutoCorrector c;c.configure(L"dictionaries",{L"en",L"uk",L"ru"});
+  PROCESS_MEMORY_COUNTERS_EX m{};
+  GetProcessMemoryInfo(GetCurrentProcess(),reinterpret_cast<PROCESS_MEMORY_COUNTERS*>(&m),sizeof(m));
+  std::cout<<"dictionary_bytes="<<c.memoryBytes()<<" private_bytes="<<m.PrivateUsage
+   <<" load_ms="<<std::chrono::duration<double,std::milli>(std::chrono::steady_clock::now()-start).count()<<'\n';
+  struct Query {std::wstring language,word; int rank;};
+  std::vector<Query> queries;
+  for(const auto *lang:{L"en",L"uk",L"ru"}) {
+   std::ifstream input(std::filesystem::path(L"dictionaries")/(std::wstring(lang)+L".txt"));
+   std::map<std::wstring,int> expected;
+   for(std::string line;std::getline(input,line);) {
+    auto tab=line.find('\t');auto word=ks::wide(line.substr(0,tab));auto rank=std::stoi(line.substr(tab+1));
+    auto [it,added]=expected.emplace(word,rank);if(!added)it->second=std::min(it->second,rank);
+   }
+   if(expected.empty())throw std::runtime_error("Missing benchmark dictionary");
+   for(auto &[word,rank]:expected) {
+    if(ks::AutoCorrectorRegressionAccess::rank(c,lang,word)!=rank)throw std::runtime_error("Dictionary rank differs from source");
+    if(ks::AutoCorrectorRegressionAccess::rank(c,lang,word+L"~")!=0)throw std::runtime_error("False dictionary hit");
+    queries.push_back({lang,word,rank});queries.push_back({lang,word+L"~",0});
+   }
+  }
+  std::mt19937 random(42);std::shuffle(queries.begin(),queries.end(),random);
+  uint64_t checksum=0,expected=0;
+  for(auto &q:queries)expected+=q.rank;
+  start=std::chrono::steady_clock::now();
+  for(int pass=0;pass<5;++pass)for(auto &q:queries)checksum+=ks::AutoCorrectorRegressionAccess::rank(c,q.language,q.word);
+  auto ms=std::chrono::duration<double,std::milli>(std::chrono::steady_clock::now()-start).count();
+  if(checksum!=expected*5)throw std::runtime_error("Lookup checksum mismatch");
+  std::cout<<"verified_words="<<queries.size()/2<<" queries="<<queries.size()*5<<" lookup_ms="<<ms
+   <<" ns_per_lookup="<<ms*1000000/(queries.size()*5)<<" checksum="<<checksum<<'\n';
+  auto fixture=std::filesystem::temp_directory_path()/(L"KSwitcher-dictionary-"+
+      std::to_wstring(GetCurrentProcessId())+L"-"+std::to_wstring(GetTickCount64())+L".txt");
+  struct RemoveFixture { std::filesystem::path path; ~RemoveFixture(){std::error_code ec;std::filesystem::remove(path,ec);} } cleanup{fixture};
+  auto put=[&](const std::string &text){ks::atomicWrite(fixture,ks::Bytes(text.begin(),text.end()));};
+  std::string text="duplicate\t9\r\nduplicate\t2\n";
+  std::vector<std::wstring> words;
+  std::vector<int> expectedRanks;
+  for(int i=129;i>=0;--i) {
+   auto word=L"prefix_"+std::to_wstring(i);
+   text+=ks::utf8(word)+"\t"+std::to_string(i+1)+"\n";
+   words.push_back(word);expectedRanks.push_back(i+1);
+  }
+  text+=std::string(160,'x')+"\t2147483647"; // Maximum length/rank, no final newline.
+  words.insert(words.end(),{std::wstring(160,L'x'),L"DUPLICATE",L"",L"prefix_",L"zzzz"});
+  expectedRanks.insert(expectedRanks.end(),{2147483647,2,0,0,0});
+  for(auto rank:{65534,65535,65536}) {
+   auto word=std::wstring(159,L'x')+wchar_t(L'y'+rank-65534);
+   text+="\n"+ks::utf8(word)+"\t"+std::to_string(rank);
+   words.push_back(word);expectedRanks.push_back(rank);
+  }
+  put(text);
+  if(ks::AutoCorrectorRegressionAccess::ranks(fixture,words)!=expectedRanks)
+   throw std::runtime_error("Block boundaries, duplicate ranks or maximum values failed");
+  for(const auto &invalid:std::vector<std::string>{"","missing-tab","x\t0","x\t-1","x\t2147483648",std::string(161,'x')+"\t1","\t1","x\t1bad"}) {
+   put(invalid);bool rejected=false;
+   try {ks::AutoCorrectorRegressionAccess::ranks(fixture,{L"x"});}catch(const std::runtime_error &){rejected=true;}
+   if(!rejected)throw std::runtime_error("Invalid dictionary was accepted");
+  }
+  const bool baseline=argc==2 && std::string(argv[1])=="--baseline";
+  if(!baseline && c.memoryBytes()>=1536*1024)throw std::runtime_error("Bundled dictionaries exceed compact memory budget");
+  std::cout<<"Passed complete dictionary equivalence and format regressions\n";
+  return 0;
+ }catch(const std::exception&e){std::cerr<<e.what()<<'\n';return 1;}
+}
@@ -0,0 +1,184 @@
+// Run from an isolated fixture folder containing KSwitcher.exe and Screenshot.exe,
+// with the normal resident stopped. Never points at the installed user's data.
+#include "storage.h"
+#include "ocr.h"
+#include "json.hpp"
+#include <commctrl.h>
+#include <psapi.h>
+#include <iostream>
+static HWND editor{};
+static bool pastedImage{};
+static LRESULT CALLBACK targetProc(HWND w,UINT message,WPARAM wp,LPARAM lp) {
+    if(message==WM_SETFOCUS && editor) {SetFocus(editor);return 0;}
+    return DefWindowProcW(w,message,wp,lp);
+}
+static void require(bool ok,const char *what) {if(!ok)throw std::runtime_error(what);std::cout<<"PASS "<<what<<'\n';}
+static void pump() {MSG m;while(PeekMessageW(&m,nullptr,0,0,PM_REMOVE)){TranslateMessage(&m);DispatchMessageW(&m);}}
+template<class F> static void until(F condition,const char *what,DWORD timeout=10000) {
+    auto end=GetTickCount64()+timeout;
+    while(!condition()){if(GetTickCount64()>=end)throw std::runtime_error(what);pump();Sleep(10);}
+}
+static LRESULT send(HWND w,UINT message,WPARAM wp=0,LPARAM lp=0) {
+    DWORD_PTR result{};
+    if(!SendMessageTimeoutW(w,message,wp,lp,SMTO_ABORTIFHUNG,5000,&result))throw std::runtime_error("window request timed out");
+    return LRESULT(result);
+}
+static void command(HWND resident,int cmd) {
+    COPYDATASTRUCT data{1,sizeof(cmd),&cmd};send(resident,WM_COPYDATA,0,LPARAM(&data));
+}
+static size_t memory(HANDLE process) {
+    ks::Bytes bytes(1024*1024);auto ws=reinterpret_cast<PSAPI_WORKING_SET_INFORMATION*>(bytes.data());
+    if(!QueryWorkingSet(process,ws,DWORD(bytes.size())))throw std::runtime_error("memory query failed");
+    size_t pages=0;for(size_t i=0;i<ws->NumberOfEntries;++i)if(!ws->WorkingSetInfo[i].Shared)++pages;
+    return pages*4096;
+}
+static std::wstring editorText() {wchar_t text[256]{};GetWindowTextW(editor,text,256);return text;}
+static LRESULT CALLBACK editProc(HWND w,UINT message,WPARAM wp,LPARAM lp,UINT_PTR,DWORD_PTR) {
+    if(message==WM_PASTE && IsClipboardFormatAvailable(CF_DIB)) {pastedImage=true;return 0;}
+    return DefSubclassProc(w,message,wp,lp);
+}
+static ks::Clip excluded(ks::Clip clip) {
+    clip.formats.push_back({0,L"ExcludeClipboardContentFromMonitorProcessing",ks::Bytes{0}});return clip;
+}
+int main() {
+    CoInitializeEx(nullptr,COINIT_APARTMENTTHREADED);
+    PROCESS_INFORMATION process{};HWND resident{},target{};ks::Clip saved;bool captured=false;int result=0;
+    try {
+        auto folder=std::filesystem::path(ks::executable()).parent_path();
+        require(folder.filename().wstring().starts_with(L"history-host-fixture-"),"isolated fixture directory");
+        require(!FindWindowW(L"KSwitcher.Main",nullptr),"normal resident is stopped");
+        WNDCLASSW targetClass{};targetClass.lpfnWndProc=targetProc;targetClass.hInstance=GetModuleHandleW(nullptr);
+        targetClass.lpszClassName=L"KSwitcher.HistoryTestDestination";RegisterClassW(&targetClass);
+        target=CreateWindowExW(0,targetClass.lpszClassName,L"KSwitcher history test destination",WS_OVERLAPPEDWINDOW|WS_VISIBLE,
+                               50,50,500,250,nullptr,nullptr,nullptr,nullptr);
+        editor=CreateWindowExW(0,L"EDIT",L"",WS_CHILD|WS_VISIBLE|ES_MULTILINE,10,10,450,180,target,nullptr,nullptr,nullptr);
+        SetWindowSubclass(editor,editProc,1,0);
+        saved=ks::readClipboard(target,128*1024*1024);captured=true;
+        ks::writeClipboard(target,excluded(ks::textClip(L"fixture clipboard")));
+        auto settings=ks::loadSettings(folder/L"missing.json",ks::readLayouts());
+        settings.autoCorrect=false;settings.writeLog=true;settings.history=true;settings.maxItems=500;settings.maxMiB=100;
+        std::filesystem::create_directories(folder/L"data");
+        ks::saveSettings(folder/L"data/settings.json",settings);
+        ks::History history(folder/L"data/history");
+        history.clear(); // This executable only runs in its dedicated fixture directory.
+        ks::Pixels pixels{1566,1068,ks::Bytes(1566*1068*4,255)};
+        auto image=ks::Clip{{ks::imageDib(pixels)}};
+        history.add(image,L"test",settings);
+        auto imageId=history.entries().front().id;
+        // Seed once rather than rewriting the encrypted index 500 times. This
+        // also avoids measuring fixture creation in the resident under test.
+        auto indexPath=folder/L"data/history/index.dat";
+        auto rows=nlohmann::json::parse(ks::unprotect(ks::readFile(indexPath,1024*1024)));
+        for(int i=0;i<499;++i) {
+            auto id=ks::lower(ks::newSnippetId().substr(1,36)),text=L"History fixture "+std::to_wstring(i);
+            auto bytes=ks::protect(ks::encodeClip(ks::textClip(text)));
+            ks::atomicWrite(folder/L"data/history"/(id+L".dat"),bytes);
+            rows.insert(rows.begin(),nlohmann::json{{"id",ks::utf8(id)},{"preview",ks::utf8(text)},
+                {"app","test"},{"bytes",bytes.size()},{"at",i+1},{"pinned",false},{"image",false},{"files",false}});
+        }
+        auto encoded=rows.dump();ks::atomicWrite(indexPath,ks::protect(ks::Bytes(encoded.begin(),encoded.end())));
+        history.reload();
+        auto textId=history.entries().front().id;
+        auto exe=folder/L"KSwitcher.exe";auto line=L"\""+exe.wstring()+L"\"";
+        STARTUPINFOW startup{sizeof(startup)};startup.dwFlags=STARTF_USESHOWWINDOW;startup.wShowWindow=SW_HIDE;
+        require(CreateProcessW(exe.c_str(),line.data(),nullptr,nullptr,FALSE,CREATE_NO_WINDOW,nullptr,folder.c_str(),&startup,&process),"start isolated resident");
+        CloseHandle(process.hThread);process.hThread=nullptr;
+        until([&]{resident=FindWindowW(L"KSwitcher.Main",nullptr);return resident!=nullptr;},"resident startup");
+        auto base=memory(process.hProcess);
+        std::string forged="{\"action\":\"clear\",\"id\":\"\",\"plain\":false}";
+        COPYDATASTRUCT forgedRequest{0x4b530200,DWORD(forged.size()),forged.data()};
+        require(send(resident,WM_COPYDATA,WPARAM(target),LPARAM(&forgedRequest))==0,
+                "history rejects requests from an untrusted process");
+        auto open=[&] {
+            require(ks::activateWindow(target),"destination foreground");SetFocus(editor);command(resident,5);
+            HWND window{};
+            until([&]{window=FindWindowW(L"KSwitcher.History",nullptr);return window&&IsWindowVisible(window);},"history startup");
+            until([&]{return send(GetDlgItem(window,102),LB_GETCOUNT)>0;},"history rows");
+            DWORD pid{};GetWindowThreadProcessId(window,&pid);
+            require(pid!=process.dwProcessId,"history belongs to a separate process");
+            return window;
+        };
+        auto close=[&](HWND window) {
+            DWORD pid{};GetWindowThreadProcessId(window,&pid);HANDLE child=OpenProcess(SYNCHRONIZE,FALSE,pid);
+            PostMessageW(window,WM_KEYDOWN,VK_ESCAPE,0); // Escape also works with focus on the window itself.
+            until([&]{return WaitForSingleObject(child,0)==WAIT_OBJECT_0;},"history helper exits after Escape");
+            CloseHandle(child);
+            require(!FindWindowW(L"KSwitcher.History",nullptr),"Escape destroys history window");
+        };
+        for(int i=0;i<3;++i){auto w=open();until([&]{return send(GetDlgItem(w,102),LB_GETCOUNT)==500;},"all history rows loaded");require(true,"all history entries visible");close(w);}
+        auto idle=memory(process.hProcess);
+        std::cout<<"MEMORY resident_before="<<base<<" after_three_closes="<<idle<<'\n';
+        require(idle<base+2*1024*1024,"repeated history does not retain UI heap in resident");
+        auto w=open();send(w,WM_COMMAND,112);
+        until([&]{history.reload();return history.entries().front().pinned;},"resident pin mutation");
+        require(history.entries().front().id==textId,"pin preserves history identity");
+        auto filter=[&](HWND window,int index) {
+            auto checkbox=GetDlgItem(window,117);
+            if(send(checkbox,BM_GETCHECK)!=(index ? BST_CHECKED : BST_UNCHECKED)) send(checkbox,BM_CLICK);
+        };
+        filter(w,1);
+        until([&]{return send(GetDlgItem(w,102),LB_GETCOUNT)==1;},"pinned filter hides unpinned entries");
+        send(GetDlgItem(w,101),WM_SETTEXT,0,LPARAM(L"History fixture 497"));
+        until([&]{return send(GetDlgItem(w,102),LB_GETCOUNT)==0;},"search cannot match an unpinned item in pinned view");
+        send(GetDlgItem(w,101),WM_SETTEXT,0,LPARAM(L"History fixture 498"));
+        until([&]{return send(GetDlgItem(w,102),LB_GETCOUNT)==1;},"history search");
+        send(w,WM_COMMAND,112);
+        until([&]{return send(GetDlgItem(w,102),LB_GETCOUNT)==0;},"unpin removes the last pinned result");
+        filter(w,0);
+        until([&]{return send(GetDlgItem(w,102),LB_GETCOUNT)==1;},"all items restores the matching unpinned entry");
+        send(w,WM_COMMAND,112);
+        filter(w,1);
+        close(w);w=open();
+        require(send(GetDlgItem(w,117),BM_GETCHECK)==BST_CHECKED,"pinned checkbox survives helper restart");
+        wchar_t query[100]{};send(GetDlgItem(w,101),WM_GETTEXT,100,LPARAM(query));
+        require(std::wstring(query)==L"History fixture 498","search survives helper restart");
+        send(w,WM_COMMAND,114);
+        HWND entry{};until([&]{entry=FindWindowW(L"KSwitcher.Entry",nullptr);return entry!=nullptr;},"full item opens");
+        DWORD childPid{};GetWindowThreadProcessId(w,&childPid);HANDLE child=OpenProcess(SYNCHRONIZE,FALSE,childPid);
+        send(GetDlgItem(w,101),WM_KEYDOWN,VK_ESCAPE);
+        require(WaitForSingleObject(child,0)==WAIT_TIMEOUT && IsWindow(entry),"full item remains usable after closing history");
+        send(entry,WM_CLOSE);
+        until([&]{return WaitForSingleObject(child,0)==WAIT_OBJECT_0;},"helper exits after last full item closes");CloseHandle(child);
+        w=open();filter(w,0);send(GetDlgItem(w,101),WM_SETTEXT,0,LPARAM(L""));
+        until([&]{return send(GetDlgItem(w,102),LB_GETCOUNT)==500;},"clear search");close(w);
+        ks::writeClipboard(target,excluded(image));
+        w=open();send(w,WM_COMMAND,111);
+        until([&]{return editorText()==L"History fixture 498";},"paste plain text into native editor");
+        until([&]{return IsClipboardFormatAvailable(CF_DIB)&&!FindWindowW(L"KSwitcher.HistoryHost",nullptr);},"image clipboard restored after paste");
+        require(ks::decodeImage(ks::readClipboard(target,64*1024*1024)).width==pixels.width,"image clipboard survives history paste");
+        auto afterPaste=memory(process.hProcess);
+        std::cout<<"MEMORY after_paste_with_image_backup="<<afterPaste<<'\n';
+        require(afterPaste<base+2*1024*1024,"image clipboard backup stays outside resident");
+        ks::writeClipboard(target,excluded(ks::textClip(L"keep clipboard")));
+        w=open();send(GetDlgItem(w,101),WM_SETTEXT,0,LPARAM(L"Image"));
+        until([&]{return send(GetDlgItem(w,102),LB_GETCOUNT)==1;},"image search");
+        pastedImage=false;send(w,WM_COMMAND,110);
+        until([&]{return pastedImage;},"image paste reaches destination");
+        until([&]{return ks::readClipboard(target).text()==L"keep clipboard";},"clipboard restored after image paste");
+        std::cout<<"MEMORY after_image_paste="<<memory(process.hProcess)<<'\n';
+        require(memory(process.hProcess)<base+2*1024*1024,"image paste does not retain full bitmap in resident");
+        until([&]{return !FindWindowW(L"KSwitcher.HistoryHost",nullptr);},"image paste helper exits");
+        w=open();send(w,WM_COMMAND,113);
+        until([&]{history.reload();return history.entries().size()==499;},"resident removes selected image");
+        GetWindowThreadProcessId(w,&childPid);child=OpenProcess(SYNCHRONIZE,FALSE,childPid);
+        // Startup update checks temporarily reject exit; retry after that
+        // operation finishes instead of treating its guard as a host leak.
+        ULONGLONG nextExit{};
+        until([&]{
+            if(WaitForSingleObject(process.hProcess,0)==WAIT_OBJECT_0) return true;
+            if(GetTickCount64()>=nextExit) {
+                command(resident,99);nextExit=GetTickCount64()+500;
+            }
+            return false;
+        },"resident accepts exit after startup update check",30000);
+        until([&]{return WaitForSingleObject(child,0)==WAIT_OBJECT_0;},"resident shutdown closes history helper");
+        CloseHandle(child);resident=nullptr;
+        std::cout<<"PASS isolated history host suite\n";
+    } catch(const std::exception &e){std::cerr<<"FAIL "<<e.what()<<" editor="<<ks::utf8(editorText())<<" foreground="<<(GetForegroundWindow()==target)<<'\n';result=1;}
+    if(resident)try{command(resident,99);}catch(...){}
+    if(process.hProcess){if(WaitForSingleObject(process.hProcess,10000)!=WAIT_OBJECT_0){TerminateProcess(process.hProcess,1);WaitForSingleObject(process.hProcess,INFINITE);}CloseHandle(process.hProcess);}
+    if(captured)try{ks::writeClipboard(target,saved);}catch(...){result=1;}
+    if(target) DestroyWindow(target);
+    CoUninitialize();
+    return result;
+}
@@ -0,0 +1,84 @@
+// Interactive clipboard test. Run with the resident stopped; the original
+// clipboard is restored. The helper must be beside this test executable.
+#include "storage.h"
+#include "ocr.h"
+#include <algorithm>
+#include <iostream>
+static void require(bool ok,const char *name) {
+    if(!ok) throw std::runtime_error(name);
+    std::cout << "PASS " << name << '\n';
+}
+int main() {
+    CoInitializeEx(nullptr,COINIT_MULTITHREADED);
+    HWND owner=CreateWindowExW(0,L"STATIC",L"Capture test",0,0,0,0,0,HWND_MESSAGE,nullptr,nullptr,nullptr);
+    ks::Clip saved; bool captured=false; int result=0;
+    auto folder=std::filesystem::temp_directory_path()/(L"KSwitcher-image-capture-"+std::to_wstring(GetCurrentProcessId()));
+    try {
+        saved=ks::readClipboard(owner,128*1024*1024); captured=true;
+        ks::Settings settings; settings.history=true;
+        ks::History history(folder);
+        history.add(ks::textClip(L"keep pinned"),L"test",settings);
+        auto pinned=history.entries().front().id; history.pin(pinned);
+        ks::Pixels pixels{32,16,ks::Bytes(32*16*4,255)};
+        ks::Clip image{{ks::imageDib(pixels),{0,L"PNG",ks::encodePng(pixels)}}};
+        auto sequence=ks::writeClipboard(owner,image);
+        require(history.captureImage(sequence,L"capture test",settings),"helper captures image");
+        auto entries=history.entries();
+        require(entries.size()==2 && entries.front().image && entries.front().ocrState==1,"resident reloads metadata with pending OCR");
+        require(entries.front().contentHash.size()==64 && !entries.front().pixelHash.empty(),
+                "helper persists fingerprints and resident reloads them");
+        require(entries.back().id==pinned && entries.back().pinned,"helper preserves existing pinned entry");
+        auto restored=history.load(entries.front().id);
+        auto thumbnail=history.thumbnail(entries.front().id);
+        require(thumbnail.width==pixels.width && thumbnail.height==pixels.height && thumbnail.bgra==pixels.bgra,
+                "helper thumbnail preserves small image pixels");
+        bool thumbnailCancelled=false;
+        try {history.thumbnail(entries.front().id,[]{return true;});} catch(...) {thumbnailCancelled=true;}
+        require(thumbnailCancelled,"closed history cancels thumbnail work");
+        auto has=[&](const ks::Format &expected) {
+            return std::any_of(restored.formats.begin(),restored.formats.end(),[&](const ks::Format &actual) {
+                return (expected.name.empty()?actual.id==expected.id:actual.name==expected.name) && actual.data==expected.data;
+            });
+        };
+        require(has(image.formats[0]) && has(image.formats[1]),
+                "encrypted history preserves both image representations");
+        require(ks::readFile(folder/(entries.front().id+L".dat"),1024*1024)!=ks::encodeClip(restored),"saved image is encrypted");
+        require(GetClipboardSequenceNumber()==sequence,"capture leaves clipboard unchanged");
+        require(history.captureImage(sequence,L"capture test",settings) && history.entries().size()==2,"duplicate capture is not added");
+        ks::writeClipboard(owner,ks::textClip(L"new clipboard"));
+        require(!history.captureImage(sequence,L"stale",settings) && history.entries().size()==2,"stale request does not save another clipboard");
+        for(auto name : {L"ExcludeClipboardContentFromMonitorProcessing",L"Clipboard Viewer Ignore",L"CanIncludeInClipboardHistory"}) {
+            auto blocked=image; blocked.formats.push_back({0,name,ks::Bytes(4,0)});
+            sequence=ks::writeClipboard(owner,blocked);
+            require(!history.captureImage(sequence,L"excluded",settings) && history.entries().size()==2,"clipboard privacy flag prevents capture");
+        }
+        pixels={1024,512,ks::Bytes(1024*512*4,255)};
+        sequence=ks::writeClipboard(owner,ks::Clip{{ks::imageDib(pixels)}});
+        settings.maxImageMiB=1;
+        bool rejected=false;
+        try {history.captureImage(sequence,L"oversized",settings);} catch(const std::exception &e) {
+            rejected=std::string(e.what())=="Clipboard exceeds the configured size limit";
+        }
+        require(rejected && history.entries().size()==2,"oversized image is rejected without changing index");
+        require(GetClipboardSequenceNumber()==sequence,"rejection leaves clipboard unchanged");
+        settings.maxImageMiB=20;
+        history.add(ks::Clip{{ks::imageDib(pixels)}},L"thumbnail fixture",settings);
+        auto largeId=history.entries().front().id;
+        thumbnail=history.thumbnail(largeId);
+        require(thumbnail.width==208 && thumbnail.height==104 && thumbnail.bgra.size()==208*104*4,
+                "large image returns only bounded thumbnail pixels");
+        history.remove(largeId);
+        bool missingRejected=false;
+        try {history.thumbnail(largeId);} catch(...) {missingRejected=true;}
+        require(missingRejected,"deleted image cannot be previewed or recreated");
+        for(const auto &file:std::filesystem::directory_iterator(folder))
+            require(file.path().extension()!=L".request","encrypted capture request is cleaned up");
+    } catch(const std::exception &e) {std::cerr << "FAIL " << e.what() << '\n';result=1;}
+    if(captured) try {ks::writeClipboard(owner,saved);} catch(...) {result=1;}
+    DestroyWindow(owner); CoUninitialize();
+    // Remove only the exact PID-specific fixture under the system temp directory.
+    std::error_code ignored;
+    if(std::filesystem::weakly_canonical(folder).parent_path()==std::filesystem::weakly_canonical(std::filesystem::temp_directory_path()))
+        std::filesystem::remove_all(folder,ignored);
+    return result;
+}
@@ -5,6 +5,19 @@
 #include <commctrl.h>
 #include <iostream>
 #include <cmath>
+static int settingsCloseChoice = IDCANCEL;
+static int settingsClosePrompts = 0;
+static void CALLBACK answerSettingsClose(HWND, UINT, UINT_PTR, DWORD)
+{
+    HWND dialog = FindWindowW(L"#32770", L"KSwitcher — Unsaved settings");
+    DWORD process{};
+    if (dialog && GetWindowThreadProcessId(dialog, &process) == GetCurrentThreadId() &&
+        process == GetCurrentProcessId())
+    {
+        ++settingsClosePrompts;
+        SendMessageW(dialog, WM_COMMAND, settingsCloseChoice, 0);
+    }
+}
 LRESULT CALLBACK countControlMoves(HWND w, UINT message, WPARAM wp, LPARAM lp, UINT_PTR, DWORD_PTR data)
 {
    if (message == WM_WINDOWPOSCHANGING) ++*reinterpret_cast<int *>(data);
@@ -12,11 +25,78 @@ LRESULT CALLBACK countControlMoves(HWND w, UINT message, WPARAM wp, LPARAM lp, U
 }
 namespace ks {
 struct InputRegressionAccess {
+    static bool idleUndo(App &a) {
+        a.last=LastTransform{}; a.last->at=100;
+        a.releaseIdleMemory(120100);
+        if (!a.last) return false;
+        a.busy=true;
+        a.releaseIdleMemory(120101);
+        if (!a.last) { a.busy=false; return false; }
+        a.busy=false;
+        a.releaseIdleMemory(120101);
+        return !a.last;
+    }
+    static bool releasedSync(const App &a) {
+        return a.syncSnapshot.capacity()==0 && a.syncResult.settings.capacity()==0 &&
+            a.syncResult.base.capacity()==0 && a.syncResult.conflicts.capacity()==0;
+    }
+    static bool completedSync(App &a, int mode) {
+        sampleConflicts(a);
+        auto conflicts=encodeSyncConflicts(a.pendingSyncConflicts);
+        a.syncConnection=loadSyncConfig(a.data);
+        a.syncSnapshot=encodeSettings(a.settings);
+        a.syncResult={mode!=1,sharedSyncSettings(a.settings),2,L"test"};
+        a.syncResult.base=a.syncResult.settings;
+        a.syncResult.conflicts=a.pendingSyncConflicts;
+        if(mode==2) a.syncResult.settings={1,2,3}; // Decode exception after joining.
+        a.syncWorker=std::thread([]{});
+        a.syncRunning=true; a.syncDone=true; a.busy=true;
+        a.pollSync();
+        bool retained=!a.syncSnapshot.empty() && a.syncRunning;
+        a.busy=false; a.pollSync();
+        return retained && releasedSync(a) && !a.syncRunning &&
+            encodeSyncConflicts(a.pendingSyncConflicts)==conflicts;
+    }
    static inline bool delivery = true;
    static inline int notifications = 0;
    static bool notify(const std::wstring &) { ++notifications; return delivery; }
+    static void sampleConflicts(App &a) {
+        a.conflictConnection=loadSyncConfig(a.data);
+        a.pendingSyncConflicts={{"/autoCorrectMinLength",L"Minimum word length",{'4'},{'5'}}};
+    }
+    static bool staleSync(App &a, bool connectionChanged) {
+        auto before=encodeSettings(a.settings);
+        a.syncConnection=loadSyncConfig(a.data);
+        a.syncSnapshot=before;
+        if(connectionChanged) a.syncConnection.enabled=!a.syncConnection.enabled;
+        else a.syncSnapshot.clear();
+        auto remote=a.settings; remote.recent=!remote.recent;
+        a.syncResult={true,sharedSyncSettings(remote),2,L"test"};
+        a.syncWorker=std::thread([]{});
+        a.syncRunning=true; a.syncDone=true;
+        a.pollSync();
+        return encodeSettings(a.settings)==before && !a.syncRunning &&
+            releasedSync(a) &&
+            !std::filesystem::exists(a.data/L"sync-base.bin");
+    }
+    static bool syncBackoff(App &a) {
+        a.syncRetryAfter=GetTickCount64()+15*60000;
+        auto previous=a.settings;
+        auto next=previous;
+        next.toggle=next.casing=next.translit=next.undo=next.clipboard=next.screenshot=L"";
+        next.direct.clear(); next.directIds.clear();
+        // This harness deliberately has no global keyboard hook.
+        a.applySettings(next);
+        bool preserved=a.nextSync==a.syncRetryAfter;
+        a.settings=previous;
+        a.syncRetryAfter=0;
+        return preserved;
+    }
    static void notificationSetup(App &a) { a.updateNotifier = notify; }
    static void setup(App &a) { a.hookBindings = {{Toggle,{MOD_CONTROL,VK_F12}}, {Case,{MOD_CONTROL|MOD_SHIFT,'U'}}}; }
+    static LRESULT routedKey(int code, UINT message, const KBDLLHOOKSTRUCT &key, LRESULT routed) {
+        return App::keyboardAfterHooks(code,message,(LPARAM)&key,routed);
+    }
    static bool updateTimer(App &a) {
        a.updateRunning=true; // Exercise timer scheduling without launching a network request.
        App::windowProc(a.window,WM_TIMER,5,0);
@@ -49,6 +129,25 @@ int main(int argc, char **argv) {
    try {
        INITCOMMONCONTROLSEX controls{sizeof(controls),ICC_STANDARD_CLASSES|ICC_LISTVIEW_CLASSES};
        InitCommonControlsEx(&controls);
+        {
+            HMENU menu = CreatePopupMenu(), child = CreatePopupMenu();
+            AppendMenuW(menu,MF_STRING | MF_CHECKED,1,L"&Settings…");
+            AppendMenuW(menu,MF_STRING,2,L"Copy\tCtrl+C");
+            AppendMenuW(child,MF_STRING,3,L"Rock && &Roll");
+            AppendMenuW(menu,MF_POPUP,(UINT_PTR)child,L"&Pause");
+            ks::showMenuAccessKeys(menu);
+            ks::showMenuAccessKeys(menu);
+            wchar_t label[128]{};
+            GetMenuStringW(menu,1,label,128,MF_BYCOMMAND);
+            require(std::wstring(label)==L"&Settings…\tS" &&
+                    (GetMenuState(menu,1,MF_BYCOMMAND)&MF_CHECKED),
+                    "visible menu mnemonic is idempotent and preserves item state");
+            GetMenuStringW(menu,2,label,128,MF_BYCOMMAND);
+            require(std::wstring(label)==L"Copy\tCtrl+C","existing menu shortcut hints are retained");
+            GetMenuStringW(child,3,label,128,MF_BYCOMMAND);
+            require(std::wstring(label)==L"Rock && &Roll\tR","submenu hints skip escaped ampersands");
+            DestroyMenu(menu);
+        }
        {
            ks::App app(GetModuleHandleW(nullptr),true,temp);
            ks::InputRegressionAccess::setup(app);
@@ -552,6 +651,22 @@ int main(int argc, char **argv) {
            };
            auto commands=[&] { MSG m{}; int n=0; while(PeekMessageW(&m,app.window,WM_HOTKEY,WM_HOTKEY,PM_REMOVE)) ++n; return n; };
            auto f12=event(VK_F12);
+            {
+                const auto before = app.inputVersion.load();
+                const auto recorded = app.run.keys;
+                for (UINT message : {WM_KEYDOWN, WM_KEYUP, WM_SYSKEYDOWN, WM_SYSKEYUP})
+                    require(ks::InputRegressionAccess::routedKey(HC_ACTION,message,event('A',30),7)==7,
+                            "forwarded keyboard events preserve downstream suppression");
+                require(app.inputVersion==before && app.run.keys==recorded && commands()==0,
+                        "forwarded events never track text, invalidate transactions or dispatch shortcuts");
+                require(ks::InputRegressionAccess::routedKey(-1,WM_KEYDOWN,event('A',30),0)==0 &&
+                        app.inputVersion==before,"negative hook codes do not process keyboard input");
+                require(ks::InputRegressionAccess::routedKey(HC_ACTION,WM_KEYDOWN,event('A',30,true),0)==0 &&
+                        app.inputVersion==before,"own input remains excluded after downstream routing");
+                require(ks::InputRegressionAccess::routedKey(HC_ACTION,WM_KEYDOWN,event('A',30),0)==0 &&
+                        app.inputVersion>before,"delivered remote input is still processed on the receiver");
+                app.run.reset();
+            }
            require(!app.handleKeyboard(event(VK_LCONTROL),true,0),"remote modifier passes through");
            require(app.handleKeyboard(f12,true,MOD_CONTROL),"remote Ctrl+F12 handled");
            require(app.handleKeyboard(f12,true,MOD_CONTROL),"remote repeat suppressed");
@@ -568,6 +683,9 @@ int main(int argc, char **argv) {
            require(!app.handleKeyboard(f12,true,MOD_CONTROL|MOD_SHIFT),"exact modifiers only");
            app.resetInput();
            app.handleKeyboard(event('A',0x1e),true,0);
+            if (app.run.keys!=L"a" && app.run.keys!=L"A")
+                std::cerr << "Input fixture foreground=" << (uintptr_t)GetForegroundWindow()
+                          << " recorded=" << ks::utf8(app.run.keys) << '\n';
            require(app.run.keys==L"a"||app.run.keys==L"A","external scan recorded with current CapsLock");
            auto keys=app.run.keys; auto version=app.inputVersion.load();
            for(WORD key:{WORD('V'),WORD(VK_SHIFT),WORD(VK_LEFT),WORD(VK_F15),WORD(0xE8)})
@@ -595,6 +713,141 @@ int main(int argc, char **argv) {
            fitted=ks::fitWindowRect({2000,2000,2600,2400},{-1920,0,0,1080});
            require(fitted.left==-600&&fitted.top==680&&fitted.right==0,"negative-coordinate monitor supported");
            ks::showSettings(app,false);
+            {
+                auto timer = SetTimer(nullptr, 0, 10, answerSettingsClose);
+                require(timer != 0, "settings close prompt responder");
+                SendMessageW(app.settingsWindow, WM_CLOSE, 0, 0);
+                require(!app.settingsWindow && settingsClosePrompts == 0,
+                        "unchanged settings close without prompting");
+                ks::showSettings(app,false);
+                auto settingsWindow = app.settingsWindow;
+                auto initial = SendDlgItemMessageW(settingsWindow,205,BM_GETCHECK,0,0);
+                SendDlgItemMessageW(settingsWindow,205,BM_SETCHECK,!initial,0);
+                SendMessageW(settingsWindow, WM_CLOSE, 0, 0);
+                require(IsWindow(settingsWindow) && settingsClosePrompts == 1,
+                        "cancel close preserves changed settings");
+                SendDlgItemMessageW(settingsWindow,205,BM_SETCHECK,initial,0);
+                SendMessageW(settingsWindow, WM_CLOSE, 0, 0);
+                require(!app.settingsWindow && settingsClosePrompts == 1,
+                        "reverted settings close without prompting");
+                ks::showSettings(app,false);
+                SetDlgItemTextW(app.settingsWindow,240,L"invalid");
+                settingsCloseChoice = IDNO;
+                SendMessageW(app.settingsWindow,WM_COMMAND,IDCANCEL,0);
+                require(!app.settingsWindow && settingsClosePrompts == 2,
+                        "Cancel button allows discarding invalid edits");
+                auto originalSettings = app.settings;
+                // The isolated harness has no keyboard hook; save without shortcuts.
+                app.settings.toggle = app.settings.casing = app.settings.translit =
+                    app.settings.undo = app.settings.clipboard = app.settings.screenshot = L"";
+                app.settings.direct.assign(app.layouts.size(), L"");
+                ks::showSettings(app,false);
+                SendDlgItemMessageW(app.settingsWindow,208,BM_SETCHECK,
+                                    originalSettings.writeLog ? BST_UNCHECKED : BST_CHECKED,0);
+                settingsCloseChoice = IDYES;
+                SendMessageW(app.settingsWindow,WM_CLOSE,0,0);
+                require(!app.settingsWindow && settingsClosePrompts == 3 &&
+                        app.settings.writeLog != originalSettings.writeLog &&
+                        ks::loadSettings(app.data / L"settings.json",app.layouts).writeLog == app.settings.writeLog,
+                        "Yes saves settings to disk and applies them before closing");
+                app.settings = originalSettings;
+                ks::setLoggingEnabled(originalSettings.writeLog);
+                KillTimer(nullptr,timer);
+                settingsCloseChoice = IDCANCEL;
+                ks::showSettings(app,false);
+            }
+            require(GetDlgItem(app.settingsWindow,258)!=nullptr,"sync available without local opt-in");
+            // Mnemonics only target visible controls; show without taking foreground focus.
+            ShowWindow(app.settingsWindow,SW_SHOWNOACTIVATE);
+            auto previousActive=SetActiveWindow(app.settingsWindow);
+            auto awakeBefore=SendDlgItemMessageW(app.settingsWindow,205,BM_GETCHECK,0,0);
+            MSG accessKey{}; accessKey.hwnd=GetDlgItem(app.settingsWindow,201);
+            accessKey.message=WM_SYSCHAR; accessKey.wParam=L'k'; accessKey.lParam=1LL<<29;
+            require(IsDialogMessageW(app.settingsWindow,&accessKey),"Alt+K is handled as a dialog access key");
+            MSG dispatched{};
+            while(PeekMessageW(&dispatched,nullptr,0,0,PM_REMOVE)) { TranslateMessage(&dispatched); DispatchMessageW(&dispatched); }
+            require(SendDlgItemMessageW(app.settingsWindow,205,BM_GETCHECK,0,0)!=awakeBefore,
+                    "Alt+K toggles Keep screen awake");
+            IsDialogMessageW(app.settingsWindow,&accessKey);
+            while(PeekMessageW(&dispatched,nullptr,0,0,PM_REMOVE)) { TranslateMessage(&dispatched); DispatchMessageW(&dispatched); }
+            require(SendDlgItemMessageW(app.settingsWindow,205,BM_GETCHECK,0,0)==awakeBefore,
+                    "repeated access key restores checkbox state");
+            ShowWindow(app.settingsWindow,SW_HIDE);
+            SetActiveWindow(previousActive);
+
+            DestroyWindow(app.settingsWindow);
+            ks::saveSyncConfig(app.data,ks::SyncConfig{});
+            ks::showSettings(app,false);
+            require(GetDlgItem(app.settingsWindow,258)!=nullptr,"sync button available after local opt-in");
+            SendMessageW(app.settingsWindow,WM_COMMAND,258,0);
+            auto syncWindow=FindWindowW(L"KSwitcher.Sync",nullptr);
+            require(syncWindow!=nullptr,"private sync dialog opens");
+            ShowWindow(syncWindow,SW_HIDE);
+            require((GetWindowLongPtrW(GetDlgItem(syncWindow,604),GWL_STYLE)&ES_PASSWORD)!=0,
+                    "sync password is masked");
+            require(!IsWindowEnabled(app.settingsWindow),"sync dialog owns settings interaction");
+            for(int id:{602,603,604,605,606,607,610,611,612,613,IDOK})
+                require(!IsWindowEnabled(GetDlgItem(syncWindow,id)),"disabled synchronization disables dependent controls");
+            require(IsWindowEnabled(GetDlgItem(syncWindow,601)) && IsWindowEnabled(GetDlgItem(syncWindow,609)) &&
+                    IsWindowEnabled(GetDlgItem(syncWindow,IDCANCEL)),"enable, forget password and close remain available");
+            SendMessageW(syncWindow,WM_COMMAND,612,0);
+            require(!FindWindowW(L"KSwitcher.SyncConflicts",nullptr),"disabled conflict action is ignored");
+            SendDlgItemMessageW(syncWindow,601,BM_SETCHECK,BST_CHECKED,0);
+            SendMessageW(syncWindow,WM_COMMAND,MAKEWPARAM(601,BN_CLICKED),0);
+            for(int id:{602,603,604,605,606,607,610,611,613,IDOK})
+                require(IsWindowEnabled(GetDlgItem(syncWindow,id)),"enabling synchronization immediately enables connection controls");
+            require(!ks::loadSyncConfig(app.data).enabled,"checking enable alone does not connect or persist");
+            auto enabledSync=ks::loadSyncConfig(app.data);
+            enabledSync.enabled=true;
+            enabledSync.server=L"https://sync.example.test";
+            enabledSync.username=L"test";
+            ks::saveSyncConfig(app.data,enabledSync);
+            SendMessageW(syncWindow,WM_COMMAND,MAKEWPARAM(601,BN_CLICKED),0);
+            ks::InputRegressionAccess::sampleConflicts(app);
+            SendMessageW(syncWindow,WM_COMMAND,612,0);
+            auto conflictsWindow=FindWindowW(L"KSwitcher.SyncConflicts",nullptr);
+            require(conflictsWindow!=nullptr,"per-setting conflict dialog opens");
+            ShowWindow(conflictsWindow,SW_HIDE);
+            require(SendDlgItemMessageW(conflictsWindow,620,LB_GETCOUNT,0,0)==1,"conflict shown as separate setting");
+            wchar_t conflictValue[20]{}; GetDlgItemTextW(conflictsWindow,621,conflictValue,20);
+            require(std::wstring(conflictValue)==L"4","local conflict value shown");
+            GetDlgItemTextW(conflictsWindow,622,conflictValue,20);
+            require(std::wstring(conflictValue)==L"5","remote conflict value shown");
+            for(int id:{620,621,622,623,624,IDOK,IDCANCEL}) {
+                RECT control{},client{};
+                GetWindowRect(GetDlgItem(conflictsWindow,id),&control);
+                MapWindowPoints(nullptr,conflictsWindow,reinterpret_cast<POINT*>(&control),2);
+                GetClientRect(conflictsWindow,&client);
+                require(control.left>=0&&control.top>=0&&control.right<=client.right&&control.bottom<=client.bottom,
+                        "conflict controls fit dialog");
+            }
+            SendMessageW(conflictsWindow,WM_COMMAND,623,0);
+            require(!IsWindowEnabled(syncWindow),"conflict dialog owns sync interaction");
+            SendMessageW(conflictsWindow,WM_COMMAND,IDCANCEL,0);
+            require(IsWindowEnabled(syncWindow),"closing conflict dialog restores sync window");
+            for(int id:{601,602,603,604,605,606,607,608,609,610,611,612,613,IDOK,IDCANCEL}) {
+                RECT control{},client{};
+                GetWindowRect(GetDlgItem(syncWindow,id),&control);
+                MapWindowPoints(nullptr,syncWindow,reinterpret_cast<POINT*>(&control),2);
+                GetClientRect(syncWindow,&client);
+                require(control.left>=0&&control.top>=0&&control.right<=client.right&&control.bottom<=client.bottom,
+                        "sync controls fit dialog");
+            }
+            SendDlgItemMessageW(syncWindow,601,BM_SETCHECK,BST_UNCHECKED,0);
+            SendMessageW(syncWindow,WM_COMMAND,MAKEWPARAM(601,BN_CLICKED),0);
+            require(IsWindowEnabled(GetDlgItem(syncWindow,IDOK)),"Save remains available to persist disabling sync");
+            SendMessageW(syncWindow,WM_COMMAND,IDOK,0);
+            require(!ks::loadSyncConfig(app.data).enabled,"saving disabled sync does not enable network access");
+            require(!IsWindowEnabled(GetDlgItem(syncWindow,IDOK)),"Save disables after disabled state is persisted");
+            SendMessageW(syncWindow,WM_COMMAND,IDCANCEL,0);
+            require(IsWindowEnabled(app.settingsWindow),"closing sync restores parent");
+            require(ks::InputRegressionAccess::staleSync(app,false),"in-flight sync cannot overwrite newer local edits");
+            require(ks::InputRegressionAccess::staleSync(app,true),"disconnect discards in-flight downloaded profile");
+            require(ks::InputRegressionAccess::idleUndo(app),"idle cleanup retains available/busy Undo and frees expired Undo");
+            for(int mode=0;mode<3;++mode)
+                require(ks::InputRegressionAccess::completedSync(app,mode),
+                        "completed, failed and invalid sync release buffers but preserve conflict choices");
+            require(ks::InputRegressionAccess::syncBackoff(app),"saving settings preserves authentication error backoff");
            SendMessageW(app.settingsWindow,WM_COMMAND,255,0);
            auto autoOptions=FindWindowW(L"KSwitcher.AutoOptions",nullptr);
            require(autoOptions!=nullptr,"auto-correction options open");
@@ -606,21 +859,31 @@ int main(int argc, char **argv) {
                GetWindowRect(autoOptions,&original);
                // Use a client size above the scrolling baseline at every DPI.
                UINT dpi=GetDpiForWindow(autoOptions);
-                SetWindowPos(autoOptions,nullptr,0,0,MulDiv(800,dpi,96),MulDiv(900,dpi,96),
+                SetWindowPos(autoOptions,nullptr,0,0,MulDiv(800,dpi,96),MulDiv(1100,dpi,96),
                             SWP_NOMOVE|SWP_NOZORDER|SWP_NOACTIVATE);
                RECT baseline{}; GetWindowRect(autoOptions,&baseline);
+                RECT clientBefore{}; GetClientRect(autoOptions,&clientBefore);
                for(int i=0;i<3;++i) GetWindowRect(GetDlgItem(autoOptions,411+i),&before[i]);
                GetWindowRect(GetDlgItem(autoOptions,IDOK),&buttonBefore);
                SetWindowPos(autoOptions,nullptr,0,0,baseline.right-baseline.left+240,
                             baseline.bottom-baseline.top+120,SWP_NOMOVE|SWP_NOZORDER|SWP_NOACTIVATE);
+                RECT clientAfter{}; GetClientRect(autoOptions,&clientAfter);
+                // Windows can constrain oversized windows to the current desktop.
+                // Check layout against the actual available client space.
+                int extraBeforeX=std::max(0,int(clientBefore.right)-MulDiv(560,dpi,96));
+                int extraAfterX=std::max(0,int(clientAfter.right)-MulDiv(560,dpi,96));
+                int extraY=std::max(0,int(clientAfter.bottom)-MulDiv(880,dpi,96))-
+                           std::max(0,int(clientBefore.bottom)-MulDiv(880,dpi,96));
                for(int i=0;i<3;++i) {
                    GetWindowRect(GetDlgItem(autoOptions,411+i),&after[i]);
-                    require(after[i].right-after[i].left==before[i].right-before[i].left+80 &&
-                            after[i].bottom-after[i].top==before[i].bottom-before[i].top+120,
+                    int extraX=(extraAfterX*(i+1)/3-extraAfterX*i/3)-
+                               (extraBeforeX*(i+1)/3-extraBeforeX*i/3);
+                    require(after[i].right-after[i].left==before[i].right-before[i].left+extraX &&
+                            after[i].bottom-after[i].top==before[i].bottom-before[i].top+extraY,
                            "dictionary columns share extra width and receive extra height");
                }
                GetWindowRect(GetDlgItem(autoOptions,IDOK),&buttonAfter);
-                require(buttonAfter.left-buttonBefore.left==240 && buttonAfter.top-buttonBefore.top==120,
+                require(buttonAfter.left-buttonBefore.left==extraAfterX-extraBeforeX && buttonAfter.top-buttonBefore.top==extraY,
                        "auto-correction buttons follow bottom-right corner");
                require(after[0].right<after[1].left && after[1].right<after[2].left &&
                            after[2].bottom<buttonAfter.top,
@@ -637,8 +900,19 @@ int main(int argc, char **argv) {
                        "personal dictionary field fits options window");
            }
            SetDlgItemTextW(autoOptions,412,L"Релізик\r\nрелізик, словечко");
+            SetDlgItemTextW(autoOptions,416,L" Првиіт = Привіт\r\nhelo=hello");
+            SendDlgItemMessageW(autoOptions,414,BM_SETCHECK,BST_CHECKED,0);
+            SendDlgItemMessageW(autoOptions,415,BM_SETCHECK,BST_CHECKED,0);
            SendMessageW(autoOptions,WM_COMMAND,IDOK,0);
            require(!IsWindow(autoOptions),"personal words accepted without file editing");
+            {
+                auto timer = SetTimer(nullptr,0,10,answerSettingsClose);
+                auto before = settingsClosePrompts;
+                SendMessageW(app.settingsWindow,WM_CLOSE,0,0);
+                KillTimer(nullptr,timer);
+                require(app.settingsWindow && settingsClosePrompts == before + 1,
+                        "accepted personal dictionary edits trigger unsaved settings warning");
+            }
            SendMessageW(app.settingsWindow,WM_COMMAND,255,0);
            autoOptions=FindWindowW(L"KSwitcher.AutoOptions",nullptr);
            ShowWindow(autoOptions,SW_HIDE);
@@ -646,11 +920,18 @@ int main(int argc, char **argv) {
            GetDlgItemTextW(autoOptions,412,personalWords,128);
            require(std::wstring(personalWords)==L"релізик, словечко",
                    "personal dictionary normalizes case, newlines and duplicate words");
+            wchar_t pairs[128]{};
+            GetDlgItemTextW(autoOptions,416,pairs,128);
+            require(std::wstring(pairs)==L"helo=hello\r\nпрвиіт=привіт\r\n" &&
+                    SendDlgItemMessageW(autoOptions,414,BM_GETCHECK,0,0)==BST_CHECKED &&
+                    SendDlgItemMessageW(autoOptions,415,BM_GETCHECK,0,0)==BST_CHECKED,
+                    "typo options and normalized replacement pairs survive reopening");
            SendMessageW(autoOptions,WM_COMMAND,IDCANCEL,0);
            if (!app.history) app.history=std::make_unique<ks::History>(temp/L"history-layout");
            ks::showHistory(app,false);
            auto history=app.historyWindow;
            require(history&&!IsWindowVisible(history),"history layout tested without changing focus");
+            require(!GetDlgItem(history,105),"history creates no RichEdit control before formatted content is displayed");
            {
                app.history=std::make_unique<ks::History>(temp/L"history-search");
                app.history->add(ks::textClip(L"згенеруй приклад"),L"test",app.settings);
@@ -678,6 +959,27 @@ int main(int argc, char **argv) {
                SetDlgItemTextW(history,101,L"");
                require(pumpUntil(2),"clearing search restores history");
                require(GetFocus()==originalFocus,"history search preserves focus");
+                SendDlgItemMessageW(history,102,LB_SETCURSEL,1,0);
+                ks::refreshHistory(app); // A result may still be in flight when closing.
+                SendDlgItemMessageW(history,101,WM_KEYDOWN,VK_ESCAPE,0);
+                require(!IsWindowVisible(history) && !GetDlgItem(history,105),
+                        "Escape closes history and leaves no RichEdit control");
+                SendMessageW(history,WM_TIMER,1,0); // KillTimer cannot retract a posted timer message.
+                require(pumpUntil(0),"closing history releases list strings");
+                auto until=GetTickCount64()+250;
+                while(GetTickCount64()<until) {
+                    MSG message{};
+                    while(PeekMessageW(&message,nullptr,0,0,PM_REMOVE)) {
+                        TranslateMessage(&message); DispatchMessageW(&message);
+                    }
+                    Sleep(5);
+                }
+                require(SendDlgItemMessageW(history,102,LB_GETCOUNT,0,0)==0,
+                        "late search results do not refill closed history");
+                ks::refreshHistory(app);
+                require(pumpUntil(2),"history reloads after releasing hidden rows");
+                require(SendDlgItemMessageW(history,102,LB_GETCURSEL,0,0)==1,
+                        "history retains selected record across close and reload");
            }
            auto childRect=[&](int id) { RECT r{}; GetWindowRect(GetDlgItem(history,id),&r); MapWindowPoints(nullptr,history,(POINT*)&r,2); return r; };
            RECT historyFrame{}; GetWindowRect(history,&historyFrame);
@@ -9,6 +9,7 @@ namespace ks
 {
 struct InputRegressionAccess
 {
+    static bool hasLast(App &app) { return app.last.has_value(); }
    static bool deferring(App &app)
    {
        std::lock_guard lock(app.stateMutex);
@@ -23,13 +24,34 @@ HWND host{}, field{};
 ks::Clip saved;
 bool captured = false, failed = false;
 bool conversionOnly = false;
+bool typosOnly = false;
 int pasteBehavior = 0;
 int enterPresses = 0;
 int copyFailuresRemaining = 0, copyRequests = 0;
+int droppedSelectionKeys = 0;
+bool trimCopiedSpaces = false;
+int trimmedCopies = 0;
 bool temporaryClipboardExcluded = true;
 bool clipboardAccessTimedOut = false;
+uint64_t forwardedVersion{};
+int forwardedEvents{};
+LRESULT CALLBACK forwardingHook(int code, WPARAM wp, LPARAM lp)
+{
+    if (code == HC_ACTION && reinterpret_cast<KBDLLHOOKSTRUCT *>(lp)->dwExtraInfo == 456)
+    {
+        ++forwardedEvents;
+        return 1; // Model MWB consuming source input routed to another machine.
+    }
+    return CallNextHookEx(nullptr, code, wp, lp);
+}
 LRESULT CALLBACK observeEnter(HWND w, UINT message, WPARAM wp, LPARAM lp, UINT_PTR, DWORD_PTR)
 {
+    if (message == WM_KEYDOWN && wp == VK_LEFT && droppedSelectionKeys > 0 &&
+        (GetKeyState(VK_SHIFT) & 0x8000))
+    {
+        --droppedSelectionKeys;
+        return 0;
+    }
    // This bare EDIT control is our test fixture, not a full editor with
    // clipboard retries. Keep clipboard access on its owning UI thread while
    // it handles Ctrl+C/Ctrl+V, so unrelated Windows clipboard listeners cannot
@@ -68,10 +90,42 @@ LRESULT CALLBACK observeEnter(HWND w, UINT message, WPARAM wp, LPARAM lp, UINT_P
                --copyFailuresRemaining;
                return 0;
            }
+            if (trimCopiedSpaces)
+            {
+                auto result = DefSubclassProc(w, message, wp, lp);
+                // Native EDIT closes the clipboard in its copy handler, including
+                // our outer opening. Reopen it before changing its published data.
+                if (!OpenClipboard(w))
+                {
+                    clipboardAccessTimedOut = true;
+                    return result;
+                }
+                auto handle = GetClipboardData(CF_UNICODETEXT);
+                auto data = handle ? static_cast<const wchar_t *>(GlobalLock(handle)) : nullptr;
+                if (data)
+                {
+                    std::wstring copied(data);
+                    GlobalUnlock(handle);
+                    const auto originalSize = copied.size();
+                    while (!copied.empty() && copied.back() == L' ') copied.pop_back();
+                    auto replacement = GlobalAlloc(GMEM_MOVEABLE, (copied.size() + 1) * sizeof(wchar_t));
+                    auto output = GlobalLock(replacement);
+                    memcpy(output, copied.c_str(), (copied.size() + 1) * sizeof(wchar_t));
+                    GlobalUnlock(replacement);
+                    if (!EmptyClipboard() || !SetClipboardData(CF_UNICODETEXT, replacement))
+                    {
+                        GlobalFree(replacement);
+                        clipboardAccessTimedOut = true;
+                    }
+                    else if (copied.size() != originalSize) ++trimmedCopies;
+                }
+                return result;
+            }
        }
    }
    if (message == WM_PASTE && pasteBehavior)
    {
+        if (pasteBehavior == 3) { pasteBehavior = 0; return 0; }
        if (pasteBehavior == 2) SendMessageW(w, EM_REPLACESEL, TRUE, (LPARAM)L"other!");
        return 0;
    }
@@ -205,10 +259,12 @@ LRESULT CALLBACK procedure(HWND w, UINT msg, WPARAM wp, LPARAM lp)
                break;
            case 3:
                require(text() == L"Hello World", "case conversion");
+                droppedSelectionKeys = 5;
                app->transform(ks::Case);
                break;
            case 4:
                require(text() == L"HELLO WORLD", "consecutive command reselects verified previous result");
+                require(droppedSelectionKeys == 0, "partial suffix selection recovered after dropped arrow keys");
                prepare(L"OLDghbdtn", false);
                record(L"ghbdtn");
                app->transform(ks::Direct + ru);
@@ -264,6 +320,8 @@ LRESULT CALLBACK procedure(HWND w, UINT msg, WPARAM wp, LPARAM lp)
                app->settings.autoCorrect = true;
                app->settings.switchLayout = true;
                app->settings.autoLanguages = {L"en", L"ru"};
+                // Direct fixture mutations bypass applySettings' dictionary preload.
+                app->autoPredictor.configure(L"dictionaries", app->settings.autoLanguages);
                app->settings.cycle = {app->layouts[en].id, app->layouts[ru].id};
                ActivateKeyboardLayout(app->layouts[en].handle, 0);
                prepare(L"ghbdtn ", false);
@@ -361,6 +419,7 @@ LRESULT CALLBACK procedure(HWND w, UINT msg, WPARAM wp, LPARAM lp)
                require(text() == L"ghbdtn" && rows.back().outcome == L"Original text remained",
                        "blocked paste records original text remaining in the actual editor");
                require(ks::readClipboard(app->window).text() == sentinel, "readback preserves clipboard after blocked paste");
+                require(!ks::InputRegressionAccess::hasLast(*app), "failed paste does not retain a fictional previous result");
                pasteBehavior = 2;
                prepare(L"ghbdtn", true);
                app->transform(ks::Direct + ru);
@@ -371,6 +430,7 @@ LRESULT CALLBACK procedure(HWND w, UINT msg, WPARAM wp, LPARAM lp)
                auto rows = ks::parseOperationLog(ks::wide(diagnosticLog()));
                require(text() == L"other!" && rows.back().outcome == L"Readback differs",
                        "unexpected editor content records readback mismatch");
+                require(!ks::InputRegressionAccess::hasLast(*app), "changed readback cannot seed repeat conversion");
                pasteBehavior = 0;
                prepare(L"привет", true);
                app->transform(ks::Direct + ru);
@@ -392,12 +452,177 @@ LRESULT CALLBACK procedure(HWND w, UINT msg, WPARAM wp, LPARAM lp)
                require(text() == L"привет" && diagnosticLog().size() == diagnosticStart,
                        "disabled diagnostics preserves conversion and writes no records");
                ks::setLoggingEnabled(true);
+                prepare(L"PuntoSwitcher ", true);
+                app->transform(ks::Direct + ru);
+                break;
+            case 44:
+                app->transform(ks::Direct + en);
+                break;
+            case 45:
+                require(text() == L"PuntoSwitcher ", "previous conversion restores CamelCase and trailing space");
+                droppedSelectionKeys = 5;
+                app->transform(ks::Direct + ru);
+                break;
+            case 46:
+                require(text() == ks::convertTo(L"PuntoSwitcher ", app->layouts, ru, en),
+                        "repeat conversion recovers Switcher suffix and preserves full result");
+                require(droppedSelectionKeys == 0, "CamelCase suffix regression dropped five selection keys");
+                require(ks::readClipboard(app->window).text() == sentinel,
+                        "suffix recovery restores original clipboard");
+                // Derive the actual text from the physical keys, preserving an older prefix.
+                prepare((L"OLD" + ks::convertTo(L"snipping ", app->layouts, ru, en)).c_str(), false);
+                record(L"snipping ");
+                droppedSelectionKeys = 4;
+                app->transform(ks::Direct + en);
+                break;
+            case 47:
+                require(text() == L"OLDsnipping ", "recent Cyrillic suffix recovery preserves older prefix");
+                require(droppedSelectionKeys == 0, "recent suffix regression dropped four selection keys");
+                app->settings.writeLog = true;
+                prepare(L"prefix wrong ", false);
+                record(L"other ");
+                app->transform(ks::Direct + ru);
+                break;
+            case 48:
+            {
+                auto rows = ks::parseOperationLog(ks::wide(diagnosticLog()));
+                require(text() == L"prefix wrong " && !rows.empty() &&
+                        rows.back().outcome == L"recent-verification-mismatch",
+                        "diagnostic mismatch does not replace unverified text");
+                auto details = rows.back().details;
+                require(details.find(L"selection-mismatch") != details.npos &&
+                        details.find(L"Expected selection:\r\nother ") != details.npos &&
+                        details.find(L"Read back:\r\nwrong ") != details.npos,
+                        "failed verification includes expected and copied text in exported details");
+                require(details.find(L"Copy begin number=") != details.npos &&
+                        details.find(L"Copy result number=") != details.npos &&
+                        details.find(L"Selection initial match=0") != details.npos &&
+                        details.find(L"SelectPrevious") != details.npos,
+                        "incident includes clipboard and selection stages");
+                pasteBehavior = 3;
+                prepare(L"=nhtdjuf", true);
+                app->transform(ks::Direct + ru);
+                stage = 49;
+                break;
+            }
+            case 49:
+            {
+                require(text() == L"=тревога" && pasteBehavior == 0,
+                        "native Edit retries one ignored paste only while original remains selected");
+                require(ks::readClipboard(app->window).text() == sentinel, "native paste retry restores clipboard");
+                trimCopiedSpaces = true;
+                app->settings.writeLog = false;
+                prepare(L"OLDghbdtn  NEXT", false);
+                SendMessageW(field, EM_SETSEL, 11, 11);
+                record(L"ghbdtn  ");
+                app->transform(ks::Direct + ru);
+                break;
+            }
+            case 50:
+                require(text() == L"OLDпривет  NEXT", "trimmed clipboard recovery preserves two spaces and surrounding text without logging");
+                app->transform(ks::Direct + en);
+                break;
+            case 51:
+                require(text() == L"OLDghbdtn  NEXT", "repeat conversion preserves accessibility-proven spaces");
+                app->transform(ks::Undo);
+                break;
+            case 52:
+                require(text() == L"OLDпривет  NEXT", "undo preserves accessibility-proven spaces");
+                prepare(L"ghbdtn", false);
+                record(L"ghbdtn ");
+                app->transform(ks::Direct + ru);
+                break;
+            case 53:
+                require(text() == L"ghbdtn", "missing real space cannot be inferred from tracked keys");
+                prepare(L"wrong ", false);
+                record(L"ghbdtn ");
+                app->transform(ks::Direct + ru);
+                break;
+            case 54:
+                require(text() == L"wrong ", "unrelated selection remains rejected with trimmed clipboard");
+                app->settings.autoCorrect = true;
+                app->settings.autoLanguages = {L"en", L"ru"};
+                // The worker now shares the predictor's immutable dictionaries.
+                // This fixture changes settings directly instead of applySettings.
+                app->autoPredictor.configure(L"dictionaries", app->settings.autoLanguages);
+                app->autoCorrector = ks::AutoCorrector{};
+                ActivateKeyboardLayout(app->layouts[en].handle, 0);
+                prepare(L"ghbdtn ", false);
+                record(L"ghbdtn ");
+                app->transform(ks::AutoCorrect);
+                break;
+            case 55:
+                require(text() == L"привет ", "automatic correction recovers copied trailing space without logging");
+                app->transform(ks::Undo);
+                break;
+            case 56:
+            {
+                require(text() == L"ghbdtn ", "automatic correction undo retains recovered space");
+                require(ks::readClipboard(app->window).text() == sentinel, "space recovery restores clipboard");
+                pasteBehavior = 1;
+                prepare(L"ghbdtn ", false);
+                record(L"ghbdtn ");
+                app->transform(ks::Direct + ru);
+                break;
+            }
+            case 57:
+            {
+                require(text() == L"ghbdtn " && !ks::InputRegressionAccess::hasLast(*app),
+                        "recovered selection with blocked paste clears repeat state even without logging");
+                require(trimmedCopies >= 7, "fixture actually stripped spaces during recovery scenarios");
+                pasteBehavior = 0;
+                trimCopiedSpaces = false;
+                // User-selected middle range, followed by the same command with
+                // no selection: retain both surrounding text and trailing spaces.
+                prepare(L"OLDghbdtn  NEXT", false);
+                SendMessageW(field, EM_SETSEL, 3, 11);
+                app->transform(ks::Direct + ru);
+                break;
+            }
+            case 58:
+                require(text() == L"OLDпривет  NEXT", "explicit middle selection preserves surrounding text");
+                app->transform(ks::Direct + en);
+                break;
+            case 59:
+                require(text() == L"OLDghbdtn  NEXT", "hotkey without selection reconverts only the previous middle range");
+                require(ks::readClipboard(app->window).text() == sentinel, "selected and repeated conversions restore clipboard");
                finish();
                break;
+            case 62:
+                saved = ks::readClipboard(app->window, 64 * 1024 * 1024);
+                captured = true;
+                app->ownSequence = ks::writeClipboard(app->window, ks::textClip(sentinel));
+                app->settings.snippets = {{L";r", L"unexpected{enter}"}};
+                ActivateKeyboardLayout(app->layouts[en].handle, 0);
+                prepare(L"prefix ", false);
+                forwardedVersion = app->inputVersion.load();
+                copyRequests = forwardedEvents = 0;
+                {
+                    std::vector<INPUT> inputs;
+                    for (WORD key : {WORD(VK_OEM_1), WORD('R')})
+                        for (DWORD flags : {DWORD(0), DWORD(KEYEVENTF_KEYUP)})
+                        {
+                            auto input = ks::keyboardInput(key, flags);
+                            input.ki.dwExtraInfo = 456;
+                            inputs.push_back(input);
+                        }
+                    require(SendInput((UINT)inputs.size(),inputs.data(),sizeof(INPUT))==inputs.size(),
+                            "forwarded snippet input submitted to real hook chain");
+                }
+                break;
+            case 63:
+                require(forwardedEvents==4,"downstream forwarding hook consumed every key event");
+                require(app->inputVersion==forwardedVersion && copyRequests==0,
+                        "forwarded snippet does not start tracking or clipboard work on source computer");
+                require(text()==L"prefix " && ks::readClipboard(app->window).text()==sentinel,
+                        "forwarded snippet leaves source editor and clipboard untouched");
+                stage = 30;
+                break;
            case 30:
            case 32:
            case 34:
            case 37:
+            case 60:
                // Earlier password/word tests replace the original multiline
                // editor with a single-line EDIT. Restore the snippet fixture:
                // a single-line control cannot insert the tested Enter action.
@@ -426,6 +651,11 @@ LRESULT CALLBACK procedure(HWND w, UINT msg, WPARAM wp, LPARAM lp)
                enterPresses = 0;
                copyRequests = 0;
                copyFailuresRemaining = stage == 38 ? 10 : stage == 33 ? 1 : 0;
+                if (stage == 61)
+                {
+                    pasteBehavior = 2; // Editor inserts unrelated clipboard text.
+                    app->settings.writeLog = false;
+                }
                temporaryClipboardExcluded = true;
                ActivateKeyboardLayout(app->layouts[en].handle, 0);
                prepare(L"prefix ", false);
@@ -489,6 +719,13 @@ LRESULT CALLBACK procedure(HWND w, UINT msg, WPARAM wp, LPARAM lp)
                require(ks::readClipboard(app->window).text() == sentinel,
                        "exhausted copy retries restore the clipboard");
                copyFailuresRemaining = 0;
+                stage = 60;
+                break;
+            case 61:
+                require(text() == L"prefix other! x", "incorrect snippet paste preserves following typing");
+                require(enterPresses == 0, "unverified snippet never submits Enter even without logging");
+                require(ks::readClipboard(app->window).text() == sentinel, "rejected snippet restores clipboard");
+                pasteBehavior = 0;
                finish();
                break;
            case 20:
@@ -501,6 +738,7 @@ LRESULT CALLBACK procedure(HWND w, UINT msg, WPARAM wp, LPARAM lp)
                app->settings.autoCorrect = true;
                app->settings.switchLayout = true;
                app->settings.autoLanguages = {L"en", L"ru"};
+                app->autoPredictor.configure(L"dictionaries", app->settings.autoLanguages);
                app->settings.cycle = {app->layouts[en].id, app->layouts[ru].id};
                app->autoCorrector = ks::AutoCorrector{};
                ActivateKeyboardLayout(app->layouts[en].handle, 0);
@@ -550,6 +788,7 @@ LRESULT CALLBACK procedure(HWND w, UINT msg, WPARAM wp, LPARAM lp)
                });
                require(uk != app->layouts.end(), "Ukrainian layout available for punctuation-key regression");
                app->settings.autoLanguages = {L"en", L"uk"};
+                app->autoPredictor.configure(L"dictionaries", app->settings.autoLanguages);
                app->settings.cycle = {app->layouts[en].id, uk->id};
                app->settings.autoWords[L"uk"] = {L"робить"};
                app->autoCorrector = ks::AutoCorrector{};
@@ -562,6 +801,61 @@ LRESULT CALLBACK procedure(HWND w, UINT msg, WPARAM wp, LPARAM lp)
            }
            case 22:
                require(text() == L"робить ", "automatic correction selects and converts the whole word across an internal comma");
+                app->settings.autoReplace = true;
+                app->settings.autoReplacements = {{L"helo", L"hello"}};
+                ActivateKeyboardLayout(app->layouts[en].handle, 0);
+                prepare(L"(Helo)! ", false);
+                record(L"(Helo)! ");
+                app->transform(ks::AutoCorrect);
+                break;
+            case 23:
+                require(text() == L"(Hello)! ", "explicit typo pair replaces verified text with punctuation and capital");
+                app->transform(ks::Undo);
+                break;
+            case 24:
+                require(text() == L"(Helo)! ", "Undo restores explicit typo replacement");
+                app->settings.autoReplace = false;
+                app->settings.autoTypos = true;
+                app->settings.autoWords[L"en"].push_back(L"kswitcher");
+                // Use a personal target to avoid bundled dictionary ambiguity.
+                prepare(L"kswithcer ", false);
+                record(L"kswithcer ");
+                app->transform(ks::AutoCorrect);
+                break;
+            case 25:
+                require(text() == L"kswitcher ", "dictionary typo correction replaces text in the current layout");
+                require(ks::readClipboard(app->window).text() == sentinel, "typo correction restores clipboard");
+                app->transform(ks::Undo);
+                break;
+            case 26:
+                require(text() == L"kswithcer ", "Undo restores dictionary typo correction");
+                record(L"kswithcer ");
+                app->transform(ks::AutoCorrect);
+                break;
+            case 27:
+                require(text() == L"kswithcer ", "Undo suppresses the rejected spelling correction");
+                app->settings.autoReplace = true;
+                app->settings.autoReplacements = {{L"tehh", L"the"}};
+                app->autoPredictor.configure(L"dictionaries", app->settings.autoLanguages);
+                prepare(L"", false);
+                {
+                    std::vector<INPUT> inputs;
+                    for (WORD key : std::wstring(L"TEHH X"))
+                        for (DWORD flags : {DWORD(0), DWORD(KEYEVENTF_KEYUP)})
+                        {
+                            auto input = ks::keyboardInput(key == L' ' ? VK_SPACE : key, flags);
+                            input.ki.dwExtraInfo = 123;
+                            inputs.push_back(input);
+                        }
+                    require(SendInput((UINT)inputs.size(), inputs.data(), sizeof(INPUT)) == inputs.size(),
+                            "custom typo and following word submitted without a pause");
+                }
+                break;
+            case 28:
+                require(text() == L"the x", "custom replacement through keyboard hook preserves subsequent typing");
+                app->settings.autoReplace = false;
+                app->settings.autoTypos = false;
+                if (typosOnly) { finish(); break; }
                stage = 30;
                break;
            }
@@ -586,6 +880,7 @@ LRESULT CALLBACK procedure(HWND w, UINT msg, WPARAM wp, LPARAM lp)
 int main(int argc, char **argv)
 {
    conversionOnly = argc > 1 && std::string(argv[1]) == "--conversion-only";
+    typosOnly = argc > 1 && std::string(argv[1]) == "--typos-only";
    CoInitializeEx(nullptr, COINIT_APARTMENTTHREADED);
    auto root = std::filesystem::temp_directory_path() /
                (L"KSwitcher-integration-" + std::to_wstring(GetCurrentProcessId()));
@@ -739,14 +1034,17 @@ int main(int argc, char **argv)
            field =
                CreateWindowW(L"EDIT", L"", WS_CHILD | WS_VISIBLE | WS_BORDER | ES_MULTILINE | ES_WANTRETURN,
                              20, 20, 590, 230, host, nullptr, cls.hInstance, nullptr);
-            deadline = GetTickCount64() + 30000;
+            deadline = GetTickCount64() + 60000;
            SetWindowSubclass(field, observeEnter, 1, 0);
-            if (argc > 1 && std::string(argv[1]) == "--typing-only")
+            if (typosOnly || (argc > 1 && std::string(argv[1]) == "--typing-only"))
                stage = 20;
            if (argc > 1 && std::string(argv[1]) == "--snippets-only")
-                stage = 30;
+                stage = 62;
            SetTimer(host, 1, 100, nullptr);
+            auto forwarding = SetWindowsHookExW(WH_KEYBOARD_LL,forwardingHook,GetModuleHandleW(nullptr),0);
+            require(forwarding!=nullptr,"downstream forwarding fixture installed before application hook");
            app->execute();
+            UnhookWindowsHookEx(forwarding);
        }
        std::filesystem::remove_all(root);
    }
@@ -59,6 +59,24 @@ int main(int argc, char **argv)
            app.settings.history = true;
            app.history->add(clip, L"OCR fixture", app.settings);
            auto id = app.history->entries().front().id;
+            auto isolated = app.history->recognizeImage(id, config);
+            if (isolated != text) throw std::runtime_error("Helper and in-process OCR results differ");
+            bool cancelled = false;
+            try { app.history->recognizeImage(id, config, [] { return true; }); }
+            catch (const std::exception &) { cancelled = true; }
+            if (!cancelled) throw std::runtime_error("Cancelled OCR request was executed");
+            auto invalid = config;
+            invalid.useTesseract = true;
+            invalid.tesseractPath = (temp / L"missing-tesseract.exe").wstring();
+            bool failed = false;
+            try { app.history->recognizeImage(id, invalid); }
+            catch (const std::exception &) { failed = true; }
+            if (!failed || app.history->entries().front().ocrState != 1)
+                throw std::runtime_error("Failed helper modified history metadata");
+            for (const auto &file : std::filesystem::directory_iterator(temp / L"history"))
+                if (file.path().filename().wstring().starts_with(L"ocr-"))
+                    throw std::runtime_error("OCR helper left temporary files");
+            std::cout << "PASS isolated OCR equivalence, cancellation, failure and encrypted IPC cleanup\n";
            if (tesseract)
            {
                app.history->saveOcr(id, L"old Windows result", app.settings);
@@ -5,9 +5,11 @@
 static std::wstring programs;
 static std::wstring activationExecutable, activationCommand;
 static int activationCalls{};
+static DWORD launchFlags{}; static bool inheritsHandles{};
 static BOOL WINAPI testCreateProcess(LPCWSTR path, LPWSTR command, LPSECURITY_ATTRIBUTES,
-    LPSECURITY_ATTRIBUTES, BOOL, DWORD, LPVOID, LPCWSTR, LPSTARTUPINFOW, LPPROCESS_INFORMATION)
+    LPSECURITY_ATTRIBUTES, BOOL inherit, DWORD flags, LPVOID, LPCWSTR, LPSTARTUPINFOW, LPPROCESS_INFORMATION)
 {
+    launchFlags=flags; inheritsHandles=inherit;
    ++activationCalls; activationExecutable=path; activationCommand=command;
    SetLastError(ERROR_CANCELLED); return FALSE; // Inspect activation without starting any program.
 }
@@ -55,6 +57,14 @@ int main()
        valid=id.vt==VT_CLSID && *id.puuid==ks::ActivatorId; PropVariantClear(&id);
        if(!valid) throw std::runtime_error("shortcut activator missing");
        ks::registerScreenshotNotifications(); // Registration is safe to repeat.
+        bool launchFailed=false;
+        try { ks::startScreenshotNotificationRegistration(); }
+        catch(const std::exception &) { launchFailed=true; }
+        if(!launchFailed || activationExecutable!=helper.wstring() ||
+           activationCommand!=L"\""+helper.wstring()+L"\" --register-notifications" ||
+           !(launchFlags&CREATE_NO_WINDOW) || inheritsHandles)
+            throw std::runtime_error("registration must launch the sibling helper and propagate failure");
+        activationCalls=0;
        ks::Activator activator(helper.wstring(),false);
        activator.Activate(L"HrynCo.KSwitcher.Screenshot",L"check-update",nullptr,0);
        auto main=(helper.parent_path()/L"KSwitcher.exe").wstring();
@@ -2,10 +2,69 @@
 // Including the implementation lets this integration test drive private editor state directly.
 #include "../src/screenshot.cpp"
 #include <iostream>
-int main()
+#include "stroke_improvement.h"
+int main(int argc, char **argv)
 {
    CoInitializeEx(nullptr,COINIT_APARTMENTTHREADED);
    try {
+        testStrokeImprovement();
+        if(argc>1 && std::string(argv[1])=="--save-only") {
+            auto require=[](bool ok,const char *message){if(!ok) throw std::runtime_error(message);};
+            auto root=std::filesystem::temp_directory_path()/(L"KSwitcher-save-"+std::to_wstring(GetCurrentProcessId()));
+            std::filesystem::create_directories(root);
+            struct Cleanup {std::filesystem::path root; ~Cleanup(){std::error_code ec; std::filesystem::remove_all(root,ec);}} cleanup{root};
+            ks::ScreenshotHost app{GetModuleHandleW(nullptr)};
+            ks::Capture c(app);
+            c.image=std::make_unique<ks::Surface>(320,240);
+            PatBlt(c.image->dc,0,0,320,240,WHITENESS);
+            c.marks={ks::Mark{{40,40},{180,140},0}};
+            auto expected=ks::decodeImage(ks::screenshotClip(c.image->dc,320,240,c.marks));
+            for(size_t i=3;i<expected.bgra.size();i+=4) expected.bgra[i]=255;
+            auto path=root/L"Знімок.png";
+            const auto clipboard=GetClipboardSequenceNumber();
+            ks::saveToFile(nullptr,c,path);
+            ks::Clip encoded{{{0,L"PNG",ks::readFile(path,16*1024*1024)}}};
+            auto actual=ks::decodeImage(encoded);
+            require(actual.width==320 && actual.height==240 && actual.bgra==expected.bgra,
+                    "PNG export preserves full resolution, annotations and opaque pixels");
+            require(c.savedPath==path && c.copied,"successful save records destination and exported state");
+            require(GetClipboardSequenceNumber()==clipboard,"saving does not change clipboard");
+            c.remember(c.marks); c.marks.clear();
+            require(!c.copied,"editing after save marks changes unexported");
+            ks::save(nullptr,c);
+            actual=ks::decodeImage(ks::Clip{{{0,L"PNG",ks::readFile(path,16*1024*1024)}}});
+            require(actual.bgra!=expected.bgra && c.copied,"Save overwrites remembered path with current edits without a dialog");
+            c.copied=false;
+            ks::save(nullptr,c,true,[](LPOPENFILENAMEW dialog)->BOOL {
+                if(!(dialog->Flags&OFN_OVERWRITEPROMPT) || std::wstring(dialog->lpstrDefExt)!=L"png" ||
+                   !std::wstring(dialog->lpstrFile).ends_with(L"Знімок.png"))
+                    throw std::runtime_error("Save As dialog must preserve filename, PNG extension and overwrite confirmation");
+                return FALSE;
+            });
+            require(!c.copied && c.savedPath==path,"cancelled Save As preserves dirty state and remembered path");
+            auto another=root/L"Another.png";
+            ks::save(nullptr,c,true,[](LPOPENFILENAMEW dialog)->BOOL {
+                auto destination=std::filesystem::path(dialog->lpstrFile).parent_path()/L"Another.png";
+                wcscpy_s(dialog->lpstrFile,dialog->nMaxFile,destination.c_str());
+                return TRUE;
+            });
+            require(c.savedPath==another && std::filesystem::exists(path),"new destination preserves previous file");
+            c.copied=false;
+            bool failed=false;
+            try {ks::saveToFile(nullptr,c,root/L"missing"/L"fail.png");} catch(const std::exception &){failed=true;}
+            require(failed && !c.copied && c.savedPath==another,"failed save preserves dirty state and previous destination");
+            require(std::distance(std::filesystem::directory_iterator(root),std::filesystem::directory_iterator{})==2,
+                    "saving leaves no temporary files");
+            bool invalid=false;
+            try {ks::save(nullptr,c,true,[](LPOPENFILENAMEW dialog)->BOOL {
+                auto destination=std::filesystem::path(dialog->lpstrFile).parent_path()/L"Wrong.jpg";
+                wcscpy_s(dialog->lpstrFile,dialog->nMaxFile,destination.c_str()); return TRUE;
+            });} catch(const std::exception &){invalid=true;}
+            require(invalid && !std::filesystem::exists(root/L"Wrong.jpg"),"PNG export rejects a misleading file extension");
+            CoUninitialize();
+            std::cout<<"Passed screenshot PNG save regressions without opening windows\n";
+            return 0;
+        }
        INITCOMMONCONTROLSEX controls{sizeof(controls),ICC_STANDARD_CLASSES}; InitCommonControlsEx(&controls);
        ks::ScreenshotHost app{GetModuleHandleW(nullptr)};
        app.window=CreateWindowW(L"STATIC",L"",0,0,0,0,0,HWND_MESSAGE,nullptr,app.instance,nullptr);
@@ -24,6 +83,180 @@ int main()
        require(c.pencilCursor!=nullptr,"pencil drawing cursor loads");
        require(c.freehand && !c.pointer && ks::toolCursor(c)==c.pencilCursor,
                "new screenshot editor starts with the pencil tool");
+        {
+            require(GetDlgItem(window,36)!=nullptr,"triangle has a dedicated toolbar button");
+            SendMessageW(window,WM_KEYDOWN,'G',0);
+            require(c.shape==ks::ScreenshotShape::Triangle && c.arrow && !c.freehand,"G selects triangle drawing tool");
+            auto mouse=[&](UINT message,POINT p) {
+                int x=c.view.left+MulDiv(p.x,c.view.right-c.view.left,c.image->width);
+                int y=c.view.top+MulDiv(p.y,c.view.bottom-c.view.top,c.image->height);
+                SendMessageW(window,message,message==WM_LBUTTONUP?0:MK_LBUTTON,MAKELPARAM(x,y));
+            };
+            mouse(WM_LBUTTONDOWN,{80,80}); mouse(WM_LBUTTONUP,{220,180});
+            require(c.marks.size()==1 && c.marks[0].shape==ks::ScreenshotShape::Triangle && c.marks[0].points.size()==4,
+                    "triangle tool creates a closed three-vertex shape");
+            auto triangle=c.marks[0];
+            for(double angle:{0.0,37.0,90.0,-125.0}) for(int i=0;i<3;++i) {
+                auto original=triangle; original.rotation=angle;
+                auto vertices=ks::shapeOutline(original);
+                auto part=ks::MarkPart(int(ks::MarkPart::Vertex0)+i);
+                require(ks::hitScreenshotMark(original,vertices[i],4)==part,"each rotated triangle vertex has its own handle");
+                POINT target{vertices[i].x+13,vertices[i].y-9};
+                auto changed=ks::dragScreenshotMark(original,part,vertices[i],target,320,240);
+                auto moved=ks::shapeOutline(changed);
+                for(int j=0;j<3;++j) {
+                    auto expected=j==i?target:vertices[j];
+                    require(std::abs(moved[j].x-expected.x)<=2 && std::abs(moved[j].y-expected.y)<=2,
+                            "dragging one vertex preserves both other world vertices after rotation");
+                }
+                require(changed.points.front().x==changed.points.back().x && changed.points.front().y==changed.points.back().y,
+                        "triangle remains closed after editing any vertex");
+            }
+            auto vertices=ks::shapeOutline(triangle);
+            mouse(WM_LBUTTONDOWN,vertices[0]);
+            require(c.part==ks::MarkPart::Vertex0,"mouse selects apex vertex");
+            mouse(WM_LBUTTONUP,{vertices[0].x+20,vertices[0].y+10});
+            require(c.marks[0].points[0].x==triangle.points[0].x+20 && c.marks[0].points[1].x==triangle.points[1].x,
+                    "mouse vertex drag changes only requested corner");
+            SendMessageW(window,WM_COMMAND,12,0);
+            require(c.marks[0].points[0].x==triangle.points[0].x,"undo restores triangle vertex");
+            SendMessageW(window,WM_COMMAND,18,0);
+            require(c.marks[0].points[0].x==triangle.points[0].x+20,"redo reapplies triangle vertex edit");
+            c.marks.clear(); c.selected=-1; c.history=ks::ScreenshotHistory{};
+            require(GetDlgItem(window,37)!=nullptr,"trapezoid has a dedicated toolbar button");
+            SendMessageW(window,WM_KEYDOWN,'B',0);
+            require(c.shape==ks::ScreenshotShape::Trapezoid && c.arrow && !c.freehand,"B selects trapezoid tool");
+            mouse(WM_LBUTTONDOWN,{60,70}); mouse(WM_LBUTTONUP,{240,180});
+            require(c.marks.size()==1 && c.marks[0].shape==ks::ScreenshotShape::Trapezoid && c.marks[0].points.size()==5 && !c.marks[0].isHighlight(),
+                    "trapezoid tool creates a closed shape with unequal parallel bases");
+            auto trapezoid=c.marks[0];
+            require(trapezoid.points[0].y==trapezoid.points[1].y && trapezoid.points[2].y==trapezoid.points[3].y &&
+                    trapezoid.points[1].x-trapezoid.points[0].x<trapezoid.points[2].x-trapezoid.points[3].x,"toolbar trapezoid has parallel unequal bases");
+            mouse(WM_LBUTTONDOWN,trapezoid.to); mouse(WM_LBUTTONUP,{260,200});
+            require(c.marks[0].to.x==260 && c.marks[0].points[0].y==c.marks[0].points[1].y,"trapezoid resizes as a shape");
+            auto grip=ks::screenshotShapeRotationHandle(c.marks[0]);
+            auto rotated=ks::dragScreenshotMark(c.marks[0],ks::MarkPart::Rotation,grip,{280,135},320,240);
+            require(rotated.rotation!=0 && rotated.shape==ks::ScreenshotShape::Trapezoid,"trapezoid supports shape rotation");
+            SendMessageW(window,WM_COMMAND,12,0); require(c.marks[0].to.x==240,"undo trapezoid resize");
+            SendMessageW(window,WM_COMMAND,12,0); require(c.marks.empty(),"undo trapezoid creation");
+            SendMessageW(window,WM_COMMAND,18,0); require(c.marks[0].shape==ks::ScreenshotShape::Trapezoid,"redo trapezoid creation");
+            c.marks.clear(); c.selected=-1; c.history=ks::ScreenshotHistory{};
+            SendMessageW(window,WM_COMMAND,21,0);
+        }
+        {
+            for(auto kind:{ks::ScreenshotShape::Rectangle,ks::ScreenshotShape::Circle,ks::ScreenshotShape::Ellipse,ks::ScreenshotShape::Triangle})
+            for(bool recognized:{false,true}) {
+                if(kind==ks::ScreenshotShape::Triangle && !recognized) continue;
+                ks::Mark shape{{100,90},{200,170},0}; shape.shape=kind; shape.ends=ks::LineEnds::None;
+                if(kind==ks::ScreenshotShape::Circle) shape.to.y=190;
+                if(recognized) shape.points=kind==ks::ScreenshotShape::Triangle?
+                    std::vector<POINT>{{150,90},{200,170},{100,170},{150,90}}:ks::shapeOutline(shape);
+                auto grip=ks::screenshotShapeRotationHandle(shape);
+                POINT center{(shape.from.x+shape.to.x)/2,(shape.from.y+shape.to.y)/2};
+                POINT right{center.x+center.y-grip.y,center.y};
+                auto rotated=ks::dragScreenshotMark(shape,ks::MarkPart::Rotation,grip,right,320,240);
+                require(std::abs(rotated.rotation-90)<.01 && rotated.from.x==shape.from.x && rotated.to.y==shape.to.y,
+                        "all native and recognized shapes rotate around their center");
+                auto corner=ks::rotateShapePoint(rotated,rotated.to);
+                require(ks::hitScreenshotMark(rotated,corner,4)==(kind==ks::ScreenshotShape::Triangle?ks::MarkPart::Vertex1:ks::MarkPart::End),"rotated resize handles remain hittable");
+                auto fixed=ks::rotateShapePoint(rotated,rotated.from);
+                auto resized=ks::dragScreenshotMark(rotated,ks::MarkPart::End,corner,{corner.x-15,corner.y+20},320,240);
+                auto stillFixed=ks::rotateShapePoint(resized,resized.from);
+                require(std::abs(stillFixed.x-fixed.x)<=1 && std::abs(stillFixed.y-fixed.y)<=1 && resized.rotation==90,
+                        "resizing rotated shapes keeps the opposite world corner fixed");
+                auto snapped=ks::dragScreenshotMark(shape,ks::MarkPart::Rotation,grip,{center.x+60,center.y-20},320,240,true);
+                require(std::abs(std::remainder(snapped.rotation,15))<.01,"Shift snaps shape rotation to 15 degrees");
+                auto cloned=ks::cloneScreenshotMark(rotated,{rotated},320,240);
+                require(cloned.rotation==rotated.rotation && cloned.shape==kind,"clone preserves shape rotation");
+                auto boundary=ks::shapeOutline(shape).front();
+                std::vector<ks::Mark> linked{shape,{{20,20},boundary,0}};
+                ks::linkScreenshotEndpoint(linked[1],false,boundary,linked,4);
+                require(linked[1].toLink.target!=0,"connector attaches to shape before rotation");
+                linked[0].rotation=90; ks::resolveScreenshotLinks(linked);
+                auto expected=ks::rotateShapePoint(linked[0],boundary);
+                require(std::abs(linked[1].to.x-expected.x)<=1 && std::abs(linked[1].to.y-expected.y)<=1,
+                        "connector follows rotated shape boundary");
+            }
+            ks::Mark shape{{100,90},{200,170},0}; shape.shape=ks::ScreenshotShape::Rectangle;
+            c.marks={shape}; c.selected=0;
+            auto mouse=[&](UINT message,POINT p) {
+                auto x=c.view.left+MulDiv(p.x,c.view.right-c.view.left,c.image->width);
+                auto y=c.view.top+MulDiv(p.y,c.view.bottom-c.view.top,c.image->height);
+                SendMessageW(window,message,message==WM_LBUTTONUP?0:MK_LBUTTON,MAKELPARAM(x,y));
+            };
+            auto grip=ks::screenshotShapeRotationHandle(shape,double(c.unit)*c.image->width/(c.view.right-c.view.left));
+            require(ks::markAt(c,grip).second==ks::MarkPart::Rotation,"shape rotation grip is distinct from thickness grip");
+            mouse(WM_LBUTTONDOWN,grip); mouse(WM_LBUTTONUP,{150+130-grip.y,130});
+            require(std::abs(c.marks[0].rotation-90)<1,"mouse rotation updates selected shape");
+            SendMessageW(window,WM_COMMAND,12,0); require(c.marks[0].rotation==0,"undo restores original shape orientation");
+            SendMessageW(window,WM_COMMAND,18,0); require(std::abs(c.marks[0].rotation-90)<1,"redo restores shape rotation");
+            c.selected=0;
+            ks::Surface rotatedPixels(320,240); PatBlt(rotatedPixels.dc,0,0,320,240,WHITENESS);
+            auto rendered=ks::decodeImage(ks::screenshotClip(rotatedPixels.dc,320,240,c.marks));
+            auto pixel=(100*320+190)*4;
+            require(rendered.bgra[pixel+2]==GetRValue(shape.color) && rendered.bgra[pixel+1]==GetGValue(shape.color),
+                    "export renders rotated shape at its new boundary");
+            POINT center{(c.canvas.left+c.canvas.right)/2,(c.canvas.top+c.canvas.bottom)/2};
+            ks::zoomCanvas(window,c,2,center);
+            grip=ks::screenshotShapeRotationHandle(c.marks[0],double(c.unit)*c.image->width/(c.view.right-c.view.left));
+            require(ks::markAt(c,grip).second==ks::MarkPart::Rotation,"rotation grip works on zoomed canvas");
+            ks::zoomCanvas(window,c,1,center,true);
+            c.marks.clear(); c.selected=-1; c.history=ks::ScreenshotHistory{};
+        }
+        {
+            BYTE savedKeys[256]{},keys[256]{}; GetKeyboardState(savedKeys);
+            std::copy(savedKeys,savedKeys+256,keys); keys[VK_CONTROL]=0x80; SetKeyboardState(keys);
+            auto fit=c.view;
+            SendMessageW(window,WM_KEYDOWN,VK_OEM_PLUS,0);
+            require(c.zoom==1.25 && c.view.right-c.view.left>fit.right-fit.left,"Ctrl+plus zooms canvas");
+            SendMessageW(window,WM_KEYDOWN,VK_SUBTRACT,0);
+            require(std::abs(c.zoom-1)<.001,"Ctrl+numpad minus zooms out");
+            SendMessageW(window,WM_KEYDOWN,VK_ADD,0);
+            SendMessageW(window,WM_KEYDOWN,VK_OEM_MINUS,0);
+            require(std::abs(c.zoom-1)<.001,"both keyboard plus/minus variants work");
+            POINT center{(c.canvas.left+c.canvas.right)/2,(c.canvas.top+c.canvas.bottom)/2};
+            ks::zoomCanvas(window,c,4,center);
+            POINT anchor{center.x+12,center.y+8},screen=anchor; ClientToScreen(window,&screen);
+            auto before=ks::imagePoint(c,anchor,false); double zoom=c.zoom;
+            SendMessageW(window,WM_MOUSEWHEEL,MAKEWPARAM(MK_CONTROL,60),MAKELPARAM(screen.x,screen.y));
+            require(c.zoom==zoom,"partial wheel delta waits for a full step");
+            SendMessageW(window,WM_MOUSEWHEEL,MAKEWPARAM(MK_CONTROL,60),MAKELPARAM(screen.x,screen.y));
+            auto after=ks::imagePoint(c,anchor,false);
+            require(c.zoom>zoom && std::abs(before.x-after.x)<=1 && std::abs(before.y-after.y)<=1,
+                    "Ctrl+wheel zoom keeps image point under cursor");
+            require(!c.history.canUndo(),"zoom does not add image edits to undo history");
+            // A fixed zoom can still fit inside a high-DPI editor. Size the
+            // fixture from the actual viewport, with room for the tested drag
+            // on both axes, then start from a centered view.
+            const double panZoom=std::max({1.0,
+                double(c.canvas.right-c.canvas.left+128)/(c.view.right-c.view.left),
+                double(c.canvas.bottom-c.canvas.top+128)/(c.view.bottom-c.view.top)});
+            ks::zoomCanvas(window,c,panZoom,center);
+            c.panX=c.panY=0; ks::layout(window,c);
+            require(c.view.left+15<c.canvas.left && c.view.top+10<c.canvas.top &&
+                    c.view.right>c.canvas.right && c.view.bottom>c.canvas.bottom,
+                    "pan fixture has drag clearance on both axes within the supported zoom range");
+            auto view=c.view;
+            SendMessageW(window,WM_MBUTTONDOWN,MK_MBUTTON,MAKELPARAM(center.x,center.y));
+            SendMessageW(window,WM_MOUSEMOVE,MK_MBUTTON,MAKELPARAM(center.x+15,center.y+10));
+            SendMessageW(window,WM_MBUTTONUP,0,MAKELPARAM(center.x+15,center.y+10));
+            require(c.view.left==view.left+15 && c.view.top==view.top+10 && !c.panning,"middle drag pans enlarged canvas");
+            keys[VK_CONTROL]=0; SetKeyboardState(keys);
+            auto a=ks::imagePoint(c,center),b=ks::imagePoint(c,{center.x+30,center.y+20});
+            SendMessageW(window,WM_LBUTTONDOWN,MK_LBUTTON,MAKELPARAM(center.x,center.y));
+            SendMessageW(window,WM_LBUTTONUP,0,MAKELPARAM(center.x+30,center.y+20));
+            require(c.marks.size()==1 && c.marks[0].from.x==a.x && c.marks[0].to.x==b.x && c.marks[0].to.y==b.y,
+                    "drawing after zoom and pan uses image coordinates");
+            auto original=c.marks[0];
+            keys[VK_CONTROL]=0x80; SetKeyboardState(keys);
+            SendMessageW(window,WM_KEYDOWN,'0',0);
+            require(c.zoom==1 && c.panX==0 && c.panY==0 && c.marks[0].from.x==original.from.x && c.marks[0].to.x==original.to.x,
+                    "Ctrl+0 resets view without transforming annotations");
+            ks::zoomCanvas(window,c,1e6,center); require(c.zoom==16,"zoom has upper bound");
+            ks::zoomCanvas(window,c,1e-6,center); require(c.zoom==.1,"zoom has lower bound");
+            SendMessageW(window,WM_KEYDOWN,'0',0); SetKeyboardState(savedKeys);
+            c.marks.clear(); c.selected=-1; c.history=ks::ScreenshotHistory{};
+        }
        {
            BYTE savedKeys[256]{},keys[256]{}; GetKeyboardState(savedKeys);
            std::copy(savedKeys,savedKeys+256,keys); keys[VK_SHIFT]=0; SetKeyboardState(keys);
@@ -32,6 +265,57 @@ int main()
                int y=c.view.top+MulDiv(p.y,c.view.bottom-c.view.top,c.image->height);
                SendMessageW(window,message,(message==WM_LBUTTONUP?0:MK_LBUTTON)|(shift?MK_SHIFT:0),MAKELPARAM(x,y));
            };
+            mouse(WM_LBUTTONDOWN,{30,190});
+            for(int x=35;x<=200;x+=5) mouse(WM_MOUSEMOVE,{x,190+(x%10?2:-2)});
+            auto original=c.stroke.points;
+            mouse(WM_LBUTTONUP,c.stroke.to);
+            require(c.marks.size()==1,"improved stroke is one object");
+            require(!c.marks[0].freehand && c.marks[0].points.empty() &&
+                    c.marks[0].shape==ks::ScreenshotShape::None && !c.marks[0].isHighlight(),
+                    "near-straight pencil stroke becomes an editable line on mouse release");
+            require(c.marks[0].color==c.currentColor && c.marks[0].thickness==3 &&
+                    c.marks[0].style==c.lineStyle && c.marks[0].ends==c.freehandEnds,
+                    "line recognition preserves drawing style");
+            auto improved=c.marks.back().points;
+            SendMessageW(window,WM_COMMAND,12,0);
+            require(c.marks.size()==1 && c.marks.back().freehand && c.marks.back().points.size()==original.size() &&
+                    std::equal(original.begin(),original.end(),c.marks.back().points.begin(),
+                        [](POINT a,POINT b){return a.x==b.x && a.y==b.y;}),"first undo restores exact raw stroke");
+            SendMessageW(window,WM_COMMAND,12,0);
+            require(c.marks.empty(),"second undo removes stroke");
+            SendMessageW(window,WM_COMMAND,18,0); SendMessageW(window,WM_COMMAND,18,0);
+            require(c.marks.size()==1 && !c.marks.back().freehand && c.marks.back().points.size()==improved.size(),"redo restores improvement");
+            c.marks.clear(); c.selected=-1; c.history=ks::ScreenshotHistory{};
+            mouse(WM_LBUTTONDOWN,{180,120});
+            for(int i=1;i<=120;++i) {
+                double a=i*2*3.141592653589793/120;
+                mouse(WM_MOUSEMOVE,{LONG(std::lround(130+50*std::cos(a))),LONG(std::lround(120+50*std::sin(a)))});
+            }
+            mouse(WM_LBUTTONUP,c.stroke.to);
+            require(c.marks.size()==1 && c.marks[0].shape==ks::ScreenshotShape::Circle &&
+                    !c.marks[0].freehand && !c.marks[0].isHighlight(),"recognized circle is a shape, not a pencil or highlight");
+            auto circle=c.marks[0];
+            require(ks::hitScreenshotMark(circle,circle.to,6)==ks::MarkPart::End,"recognized shape exposes bounding-box resize handle");
+            mouse(WM_LBUTTONDOWN,circle.to);
+            mouse(WM_MOUSEMOVE,{circle.to.x+30,circle.to.y+20});
+            mouse(WM_LBUTTONUP,{circle.to.x+30,circle.to.y+20});
+            require(c.marks[0].to.x>circle.to.x && c.marks[0].to.x-c.marks[0].from.x==c.marks[0].to.y-c.marks[0].from.y &&
+                    c.marks[0].points[0].x>circle.points[0].x,"dragging recognized circle handle scales the whole circle proportionally");
+            SendMessageW(window,WM_COMMAND,12,0);
+            require(c.marks[0].shape==ks::ScreenshotShape::Circle && c.marks[0].to.x==circle.to.x,"undo restores shape size");
+            SendMessageW(window,WM_COMMAND,12,0);
+            require(c.marks[0].freehand && c.marks[0].shape==ks::ScreenshotShape::None,"undo recognition restores editable pencil stroke");
+            SendMessageW(window,WM_COMMAND,18,0);
+            require(c.marks[0].shape==ks::ScreenshotShape::Circle,"redo restores shape type");
+            for(auto kind:{ks::ScreenshotShape::Rectangle,ks::ScreenshotShape::Ellipse,ks::ScreenshotShape::Triangle}) {
+                auto shape=circle; shape.shape=kind;
+                auto resized=ks::dragScreenshotMark(shape,ks::MarkPart::End,shape.to,{shape.to.x+50,shape.to.y+20},320,240);
+                require(resized.points[0].x!=shape.points[0].x && resized.points[24].y!=shape.points[24].y,
+                        "shape resize transforms all outline points in both axes");
+                auto moved=ks::cloneScreenshotMark(resized,{resized},320,240);
+                require(moved.shape==kind && !moved.isHighlight(),"clone preserves recognized shape type");
+            }
+            c.marks.clear(); c.selected=-1; c.history=ks::ScreenshotHistory{};
            mouse(WM_LBUTTONDOWN,{40,40},true);
            mouse(WM_MOUSEMOVE,{100,50},true);
            require(c.stroke.to.x==100 && c.stroke.to.y==40,"Shift constrains pencil horizontally");
@@ -170,8 +454,16 @@ int main()
            c.marks={{{20,20},{120,20},0}};
            require(ks::actionCursor(c,{0,ks::MarkPart::Body},true)==LoadCursorW(nullptr,IDC_SIZEALL),"move cursor overrides drawing tool");
            require(ks::actionCursor(c,{0,ks::MarkPart::Rotation},true)==LoadCursorW(nullptr,IDC_HAND),"rotation cursor overrides drawing tool");
-            require(ks::actionCursor(c,{0,ks::MarkPart::End},true)==LoadCursorW(nullptr,IDC_SIZEWE),"endpoint resize overrides drawing tool");
+            for(auto part:{ks::MarkPart::Start,ks::MarkPart::End,ks::MarkPart::Radius,
+                           ks::MarkPart::Label,ks::MarkPart::Vertex0,ks::MarkPart::Vertex1,ks::MarkPart::Vertex2})
+                require(ks::actionCursor(c,{0,part},true)==LoadCursorW(nullptr,IDC_SIZEALL),
+                        "freely movable handles use four-direction cursor for every drawing tool");
            require(ks::actionCursor(c,{0,ks::MarkPart::Thickness},true)==LoadCursorW(nullptr,IDC_SIZENS),"thickness resize is perpendicular to line");
+            c.marks[0].to={20,120};
+            require(ks::actionCursor(c,{0,ks::MarkPart::End},true)==LoadCursorW(nullptr,IDC_SIZEALL),
+                    "vertical line endpoint still moves in both axes");
+            require(ks::actionCursor(c,{0,ks::MarkPart::Thickness},true)==LoadCursorW(nullptr,IDC_SIZEWE),
+                    "vertical line thickness retains horizontal resize cursor");
        }
        c.marks.clear(); SendMessageW(window,WM_COMMAND,27,0);
        wchar_t windowTitle[128]{}; GetWindowTextW(window,windowTitle,128);
@@ -0,0 +1,125 @@
+#pragma once
+inline void testStrokeImprovement() {
+    auto require=[](bool ok,const char *message){if(!ok) throw std::runtime_error(message);};
+    for(double angle:{0.0,.37,1.57079632679,2.8}) for(bool reverse:{false,true}) {
+        std::vector<POINT> p;
+        for(int i=0;i<=20;++i) {
+            double x=i*10,y=i==0 || i==20?0:(i%3)-1;
+            p.push_back({LONG(std::lround(300+x*std::cos(angle)-y*std::sin(angle))),
+                         LONG(std::lround(300+x*std::sin(angle)+y*std::cos(angle)))});
+        }
+        if(reverse) std::reverse(p.begin(),p.end());
+        bool line=false; ks::ScreenshotShape shape{};
+        auto result=ks::improveScreenshotStroke(p,&shape,&line);
+        require(line && shape==ks::ScreenshotShape::None && result.size()==2 &&
+                result.front().x==p.front().x && result.front().y==p.front().y &&
+                result.back().x==p.back().x && result.back().y==p.back().y,
+                "recognize noisy lines at arbitrary angles and preserve directed endpoints");
+    }
+    for(auto p:std::vector<std::vector<POINT>>{
+        {{0,0},{50,1},{100,0}}, {{0,0},{0,0},{50,0},{100,0}}}) {
+        bool line=false;
+        require(ks::improveScreenshotStroke(p,nullptr,&line).size()==2 && line,
+                "recognize sparsely sampled lines and repeated mouse positions");
+    }
+    for(auto p:std::vector<std::vector<POINT>>{
+        {{0,0},{8,1},{16,0}}, {{0,0},{50,0},{40,0},{80,0},{100,0}},
+        {{0,0},{25,8},{50,12},{75,8},{100,0}},
+        {{0,0},{50,0},{51,10},{52,0},{100,0}}, {{0,0},{0,0},{0,0}}}) {
+        bool line=true;
+        ks::improveScreenshotStroke(p,nullptr,&line);
+        require(!line,"do not straighten short strokes, retracing, curves, spikes or stationary input");
+    }
+    auto path=[](std::vector<POINT> corners) {
+        std::vector<POINT> p;
+        for(size_t i=1;i<corners.size();++i) for(int j=0;j<25;++j) {
+            double t=j/25.0;
+            p.push_back({LONG(std::lround(corners[i-1].x*(1-t)+corners[i].x*t)),
+                         LONG(std::lround(corners[i-1].y*(1-t)+corners[i].y*t))});
+        }
+        p.push_back(corners.back()); return p;
+    };
+    for(bool tilted:{false,true}) {
+        auto p=path({{40,40},{240,40},{240,140},{40,140},{40,40}});
+        if(tilted) for(auto &q:p) {double x=q.x,y=q.y;q={LONG(std::lround(x*.866-y*.5+100)),LONG(std::lround(x*.5+y*.866))};}
+        for(size_t i=1;i+1<p.size();++i) p[i].y+=int(i%3)-1;
+        auto result=ks::improveScreenshotStroke(p);
+        require(result.size()==5,"recognize noisy and tilted rectangles");
+        double ax=result[1].x-result[0].x,ay=result[1].y-result[0].y;
+        double bx=result[2].x-result[1].x,by=result[2].y-result[1].y;
+        require(std::abs(ax*bx+ay*by)<300,"rectangle has perpendicular sides");
+    }
+    auto triangle=ks::improveScreenshotStroke(path({{130,30},{240,180},{30,180},{130,30}}));
+    for(auto corners:std::vector<std::vector<POINT>>{
+        {{435,172},{455,135},{481,76},{514,78},{567,78},{605,76},{631,103},{652,135},{681,171},{609,172},{539,174},{435,172}},
+        {{531,311},{553,280},{582,235},{616,236},{672,233},{686,264},{693,287},{710,318},{640,314},{531,311}},
+        {{70,40},{160,40},{220,150},{20,150},{70,40}}})
+    for(double angle:{0.0,.6,2.2}) for(bool reverse:{false,true}) {
+        auto p=path(corners);
+        for(auto &q:p) { double x=q.x,y=q.y; q={LONG(std::lround(x*std::cos(angle)-y*std::sin(angle)+700)),
+            LONG(std::lround(x*std::sin(angle)+y*std::cos(angle)+700))}; }
+        if(reverse) std::reverse(p.begin(),p.end());
+        ks::ScreenshotShape kind{}; auto result=ks::improveScreenshotStroke(p,&kind);
+        require(kind==ks::ScreenshotShape::Trapezoid && result.size()==5,"recognize hand-drawn and tilted trapezoids");
+        double ax=result[1].x-result[0].x,ay=result[1].y-result[0].y;
+        double bx=result[3].x-result[2].x,by=result[3].y-result[2].y;
+        require(std::abs(ax*by-ay*bx)/(std::hypot(ax,ay)*std::hypot(bx,by))<.025,"recognized trapezoid bases are parallel");
+    }
+    // Approximate the reported skewed square, including its small closing gap.
+    auto unevenBox=path({{662,297},{663,213},{659,199},{659,181},{691,181},{718,189},
+                        {753,195},{786,195},{775,217},{771,249},{771,289},{766,313},
+                        {745,311},{716,304},{689,300},{671,300}});
+    for(double factor:{.5,1.0,2.5}) for(bool reverse:{false,true}) {
+        auto p=unevenBox;
+        for(auto &q:p) {q.x=LONG(std::lround((q.x-650)*factor+50));q.y=LONG(std::lround((q.y-170)*factor+50));}
+        if(reverse) std::reverse(p.begin(),p.end());
+        ks::ScreenshotShape kind{};
+        auto result=ks::improveScreenshotStroke(p,&kind);
+        require(kind==ks::ScreenshotShape::Rectangle && result.size()==5,"uneven square must not become a circle");
+    }
+    require(triangle.size()==4,"recognize triangle");
+    for(double ry:{50.0,90.0}) {
+        std::vector<POINT> p;
+        for(int i=0;i<=120;++i) {double a=i*2*3.141592653589793/120;
+            p.push_back({LONG(std::lround(150+90*std::cos(a))),LONG(std::lround(150+ry*std::sin(a)))});}
+        auto result=ks::improveScreenshotStroke(p);
+        require(result.size()==97 && result.front().x==result.back().x && result.front().y==result.back().y,
+                "recognize ellipse and circle as closed outlines");
+    }
+    auto open=path({{20,20},{200,20},{200,150},{60,150}});
+    // Hand-traced approximations of the uneven loops in the reported screenshot.
+    for(auto corners:std::vector<std::vector<POINT>>{
+        {{424,408},{449,407},{474,418},{487,439},{488,461},{475,485},{453,488},{432,479},{412,458},{410,435},{416,418},{431,409}},
+        {{352,474},{373,482},{389,501},{392,518},{378,529},{351,531},{331,519},{324,504},{326,486},{339,477},{352,474}},
+        {{246,236},{221,242},{192,256},{166,271},{151,289},{154,303},{172,316},{195,315},{226,305},{246,291},{250,272},{252,252},{246,236}}}) {
+        auto result=ks::improveScreenshotStroke(path(corners));
+        require(result.size()==97,"recognize uneven hand-drawn loops from screenshot");
+    }
+    for(double size:{35.0,100.0,300.0}) for(double aspect:{.5,1.0}) for(int direction:{-1,1}) {
+        std::vector<POINT> p;
+        for(int i=0;i<=120;++i) {
+            double a=direction*(.3+i*5.85/120),r=1+.07*std::sin(3*a)+.035*std::cos(7*a);
+            double x=size*r*std::cos(a),y=size*aspect*r*std::sin(a);
+            p.push_back({LONG(std::lround(500+x*.866-y*.5)),LONG(std::lround(500+x*.5+y*.866))});
+        }
+        require(ks::improveScreenshotStroke(p).size()==97,"recognize wobbly tilted ovals with closing gaps at different sizes");
+    }
+    for(double turns:{.72,1.8}) {
+        std::vector<POINT> p;
+        for(int i=0;i<=120;++i) {double a=i*turns*2*3.141592653589793/120;
+            p.push_back({LONG(std::lround(150+90*std::cos(a))),LONG(std::lround(150+70*std::sin(a)))});}
+        auto result=ks::improveScreenshotStroke(p);
+        require(result.size()!=97,"do not close broad arcs or repeated loops into ovals");
+    }
+    auto smoothed=ks::improveScreenshotStroke(open);
+    require(smoothed.size()>5 && smoothed.front().x==20 && smoothed.back().x==60,"open outline stays open");
+    auto scribble=path({{20,20},{200,150},{200,20},{20,150},{20,20}});
+    require(ks::improveScreenshotStroke(scribble).size()>97,"crossed scribble is not a shape");
+    require(ks::improveScreenshotStroke({{1,1},{1,1},{1,1},{1,1},{1,1}}).empty(),"stationary stroke unchanged");
+    std::vector<POINT> jitter;
+    for(int i=0;i<=100;++i) jitter.push_back({20+i*2,100+(i%2?2:-2)});
+    auto smooth=ks::improveScreenshotStroke(jitter);
+    double deviation=0; for(auto p:smooth) deviation+=std::abs(p.y-100);
+    require(deviation/smooth.size()<1.5 && smooth.front().y==jitter.front().y && smooth.back().y==jitter.back().y,
+            "smoothing reduces jitter and preserves endpoints");
+}
@@ -0,0 +1,328 @@
+#include "sync.h"
+#include "json.hpp"
+#include <iostream>
+using namespace ks;
+using Json = nlohmann::json;
+namespace
+{
+int checks{};
+void require(bool condition, const char *message)
+{
+    if (!condition) throw std::runtime_error(message);
+    ++checks;
+}
+template<class F> void rejects(F f, const char *message)
+{
+    bool rejected = false;
+    try { f(); } catch (const std::exception &) { rejected = true; }
+    require(rejected, message);
+}
+Bytes bytes(const Json &j) { auto s = j.dump(); return {s.begin(), s.end()}; }
+Json parse(const Bytes &b) { return Json::parse(b.begin(), b.end()); }
+struct FakeProvider : SyncProvider
+{
+    SyncDocument remote;
+    int writes{};
+    bool race{};
+    SyncDocument read() override { return remote; }
+    uint64_t write(const Bytes &b, uint64_t expected) override
+    {
+        if (race) ++remote.revision;
+        if (expected != remote.revision) throw std::runtime_error("CAS conflict");
+        ++writes; remote = {remote.revision + 1, b}; return remote.revision;
+    }
+};
+}
+int main()
+{
+    auto root = std::filesystem::temp_directory_path() / (L"ks-sync-test-" + std::to_wstring(GetCurrentProcessId()));
+    try
+    {
+        std::filesystem::create_directories(root);
+        require(!syncVisible(root), "hidden without opt-in file");
+        require(!loadSyncConfig(root).enabled, "disabled by default");
+        SyncConfig config; config.server = L"https://bao.example.com"; config.username = L"person"; config.enabled = true;
+        validateSyncConfig(config);
+        for (const auto *server : {L"http://bao.example.com", L"https://user:pass@bao.example.com", L"https://bao.example.com/x", L"https://bao.example.com?x=1"})
+        {
+            auto invalid = config; invalid.server = server;
+            rejects([&] { validateSyncConfig(invalid); }, "reject unsafe endpoint");
+        }
+        auto invalid = config; invalid.path = L"../other";
+        rejects([&] { validateSyncConfig(invalid); }, "reject traversal");
+        invalid = config; invalid.provider = L"unknown";
+        rejects([&] { validateSyncConfig(invalid); }, "reject unsupported provider");
+        saveSyncConfig(root, config);
+        require(syncVisible(root) && loadSyncConfig(root) == config, "connection round trip");
+        auto partialConfig = config; partialConfig.keepLocalLayouts = true;
+        saveSyncConfig(root, partialConfig);
+        require(loadSyncConfig(root).keepLocalLayouts, "partial sync mode survives restart");
+        saveSyncConfig(root, config);
+        auto rawConfig = parse(readFile(root / L"sync.json", 16384));
+        require(!rawConfig.contains("password") && !rawConfig.contains("token"), "no secrets in config");
+        Settings local;
+        local.autostart = true; local.elevatedAutostart = true; local.tesseractPath = L"C:\\private\\tesseract.exe";
+        local.history = false;
+        local.snippets.push_back({L"test", L"private snippet"});
+        auto base = sharedSyncSettings(local);
+        Settings ordered = local, reordered = local;
+        ordered.directIds = {L"00000409", L"00000422"}; ordered.direct = {L"Ctrl+1", L"Ctrl+2"};
+        reordered.directIds = {L"00000422", L"00000409"}; reordered.direct = {L"Ctrl+2", L"Ctrl+1"};
+        require(sharedSyncSettings(ordered) == sharedSyncSettings(reordered), "layout enumeration does not cause sync churn");
+        auto j = parse(base);
+        require(!j.contains("startWithSystem") && !j.contains("tesseractPath") && !j.contains("historyEnabled"), "local-only fields excluded");
+        auto restored = restoreSyncSettings(base, local, {});
+        require(restored.autostart && restored.elevatedAutostart && !restored.history && restored.tesseractPath == local.tesseractPath, "preserve device settings");
+        auto hostile = j; hostile["startWithSystem"] = false;
+        rejects([&] { restoreSyncSettings(bytes(hostile), local, {}); }, "reject injected device setting");
+        hostile = j; hostile["schemaVersion"] = 2;
+        rejects([&] { restoreSyncSettings(bytes(hostile), local, {}); }, "reject future schema");
+        hostile = j; hostile["layouts"] = Json::array({"00000422"});
+        rejects([&] { restoreSyncSettings(bytes(hostile), local, {}); }, "missing layouts block destructive normalization");
+        auto left = j, right = j;
+        left["convertLastWord"] = false; right["switchSystemLayout"] = false;
+        auto merged = parse(mergeSyncSettings(base, bytes(left), bytes(right)));
+        require(merged["convertLastWord"] == false && merged["switchSystemLayout"] == false, "merge independent edits");
+        left = right = j; left["autoCorrectMinLength"] = 4; right["autoCorrectMinLength"] = 5;
+        rejects([&] { mergeSyncSettings(base, bytes(left), bytes(right)); }, "same field conflict");
+        left = right = j; left["snippets"].push_back({{"trigger", "aaa"}, {"text", "one"}});
+        right["snippets"].push_back({{"trigger", "bbb"}, {"text", "two"}});
+        require(parse(mergeSyncSettings(base, bytes(left), bytes(right)))["snippets"].size() == 3, "independent snippet additions merge");
+        require(parse(mergeSyncSettings({}, bytes(left), base))["snippets"].size() == 2,
+                "first sync merges independent additions without choosing a whole profile");
+        require(parse(mergeSyncSettings({}, base, base)) == j, "identical first sync safe");
+        {
+            auto l = j, r = j;
+            l["autoCorrectMinLength"] = 4; r["autoCorrectMinLength"] = 5;
+            l["autoCorrectNever"].push_back("localword");
+            r["autoCorrectNever"].push_back("remoteword");
+            auto plan = mergeSyncProfile({}, bytes(l), bytes(r));
+            require(plan.conflicts.size() == 1 && parse(plan.local)["autoCorrectNever"].size() == 2 &&
+                    parse(plan.remote)["autoCorrectNever"].size() == 2,
+                    "first sync merges lists while preserving scalar conflicts");
+            require(parse(plan.local)["autoCorrectMinLength"] == 4 && parse(plan.remote)["autoCorrectMinLength"] == 5,
+                    "first sync never guesses between different scalar values");
+            auto again = mergeSyncProfile(plan.base, plan.local, plan.remote);
+            require(again.conflicts.size() == 1, "first-sync conflicts survive saving the ancestor");
+            auto resolved = mergeSyncProfile(plan.base, plan.local, plan.remote, {{plan.conflicts[0], false}});
+            require(resolved.conflicts.empty() && parse(resolved.local)["autoCorrectMinLength"] == 5,
+                    "first-sync conflict can be resolved independently");
+        }
+        require(SyncIntervalMs == 600000, "background interval is ten minutes");
+        {
+            auto l = j, r = j;
+            l["autoCorrectReplacements"]["helo"] = "hello";
+            r["autoCorrectReplacements"]["wrold"] = "world";
+            auto paired = mergeSyncSettings(base, bytes(l), bytes(r));
+            require(parse(paired)["autoCorrectReplacements"].size() == 2, "independent replacement pairs merge");
+            l = r = parse(paired);
+            l["autoCorrectReplacements"].erase("helo");
+            r["autoCorrectReplacements"]["wrold"] = "worlds";
+            auto removed = mergeSyncSettings(paired, bytes(l), bytes(r));
+            auto restored = restoreSyncSettings(removed, local, {});
+            require(restored.autoReplacements.size() == 1 && restored.autoReplacements.at(L"wrold") == L"worlds",
+                    "replacement deletion merges with an independent edit and remains loadable");
+            r["autoCorrectReplacements"]["helo"] = "help";
+            require(mergeSyncProfile(paired, bytes(l), bytes(r)).conflicts.size() == 1,
+                    "replacement deletion versus edit is a conflict");
+            auto legacy = j;
+            for (auto key : {"autoCorrectReplace", "autoCorrectTypos", "autoCorrectReplacements"}) legacy.erase(key);
+            auto migrated = restoreSyncSettings(bytes(legacy), local, {});
+            require(!migrated.autoReplace && !migrated.autoTypos && migrated.autoReplacements.empty(),
+                    "older synchronized profiles default new typo modes off");
+        }
+        {
+            auto l = j, r = j;
+            l["autoCorrectMinLength"] = 4; r["autoCorrectMinLength"] = 5;
+            l["convertLastWord"] = false; r["switchSystemLayout"] = false;
+            auto plan = mergeSyncProfile(base, bytes(l), bytes(r));
+            require(plan.conflicts.size() == 1, "one conflict reported independently");
+            require(parse(plan.local)["switchSystemLayout"] == false && parse(plan.remote)["convertLastWord"] == false,
+                "nonconflicting changes reach both copies");
+            require(parse(plan.local)["autoCorrectMinLength"] == 4 && parse(plan.remote)["autoCorrectMinLength"] == 5,
+                "unresolved scalar retains both values");
+            require(parse(plan.base)["autoCorrectMinLength"] == j["autoCorrectMinLength"], "ancestor retained for unresolved setting");
+            saveSyncBase(root, config, plan.base);
+            auto again = mergeSyncProfile(loadSyncBase(root, config), plan.local, plan.remote);
+            require(again.conflicts.size() == 1, "conflict survives restart checkpoint");
+            auto choice = SyncChoice{plan.conflicts.front(), true};
+            auto resolved = mergeSyncProfile(plan.base, plan.local, plan.remote, {choice});
+            require(resolved.conflicts.empty() && parse(resolved.remote)["autoCorrectMinLength"] == 4,
+                "resolve only selected setting");
+            require(parse(resolved.remote)["switchSystemLayout"] == false, "choice preserves independent server change");
+            auto changed = parse(plan.remote); changed["autoCorrectMinLength"] = 6;
+            require(mergeSyncProfile(plan.base, plan.local, bytes(changed), {choice}).conflicts.size() == 1,
+                "stale conflict choice never overwrites new server value");
+            FakeProvider partial; partial.remote = {7, bytes(r)};
+            auto result = synchronize(partial, base, bytes(l), SyncAction::Automatic);
+            require(result.success && result.conflicts.size() == 1 && partial.writes == 1,
+                "partial synchronization commits independent fields with CAS");
+            auto encoded = encodeSyncChoices({choice});
+            require(decodeSyncChoices(encoded).front().conflict.key == choice.conflict.key, "choice IPC round trip");
+        }
+        {
+            auto id = j["snippets"][0]["id"].get<std::string>();
+            auto l = j, r = j;
+            l["snippets"][0]["trigger"] = "renamed";
+            r["snippets"][0]["text"] = "edited remotely";
+            auto merged = parse(mergeSyncSettings(base, bytes(l), bytes(r)));
+            require(merged["snippets"][0]["id"] == id && merged["snippets"][0]["trigger"] == "renamed" &&
+                merged["snippets"][0]["text"] == "edited remotely", "stable ID merges rename and text edit");
+            l = r = j; l["snippets"] = Json::array(); l["snippetTombstones"] = Json::array({id});
+            auto deletion = mergeSyncProfile(base, bytes(l), bytes(r));
+            require(deletion.conflicts.empty() && parse(deletion.remote)["snippets"].empty(), "delete beats unchanged snippet");
+            require(parse(deletion.remote)["snippetTombstones"] == Json::array({id}), "deletion marker retained");
+            auto offline = mergeSyncProfile(base, bytes(r), deletion.remote);
+            require(offline.conflicts.empty() && parse(offline.local)["snippets"].empty(), "offline copy cannot resurrect deletion");
+            r["snippets"][0]["text"] = "offline edit";
+            auto conflict = mergeSyncProfile(base, bytes(l), bytes(r));
+            require(conflict.conflicts.size() == 1, "delete versus edit is one snippet conflict");
+            auto remove = mergeSyncProfile(conflict.base, conflict.local, conflict.remote, {{conflict.conflicts[0], true}});
+            require(remove.conflicts.empty() && parse(remove.remote)["snippets"].empty(), "choose deletion");
+            auto keep = mergeSyncProfile(conflict.base, conflict.local, conflict.remote, {{conflict.conflicts[0], false}});
+            require(keep.conflicts.empty() && parse(keep.local)["snippetTombstones"].empty() &&
+                parse(keep.local)["snippets"][0]["text"] == "offline edit", "choose edited snippet removes tombstone");
+            require(mergeSyncProfile(base, bytes(l), bytes(l)).conflicts.empty(), "both delete converges");
+            auto legacy = j; legacy.erase("snippetTombstones"); legacy["snippets"][0].erase("id");
+            auto migrated = parse(mergeSyncSettings(bytes(legacy), base, bytes(legacy)));
+            require(migrated["snippets"][0]["id"] == id, "legacy profiles migrate to identical IDs");
+            auto roundtrip = decodeSettings(encodeSettings(restored), {});
+            require(snippetId(roundtrip.snippets.front()) == wide(id), "ID survives settings serialization");
+            require(newSnippetId() != newSnippetId(), "new snippet IDs are unique");
+        }
+        {
+            auto l = j, r = j;
+            l["snippets"].push_back({{"id", "new-a"}, {"trigger", "same"}, {"text", "A"}});
+            r["snippets"].push_back({{"id", "new-b"}, {"trigger", "same"}, {"text", "B"}});
+            auto collision = mergeSyncProfile(base, bytes(l), bytes(r));
+            require(collision.conflicts.size() == 2, "duplicate new triggers expose individual choices");
+            auto resolved = mergeSyncProfile(collision.base, collision.local, collision.remote,
+                {{collision.conflicts[0], true}, {collision.conflicts[1], true}});
+            require(resolved.conflicts.empty() && parse(resolved.remote)["snippets"].size() == 2, "choose one of colliding additions");
+            l = r = j; l["toggleHotkey"] = "Ctrl+Alt+F11"; r["caseHotkey"] = "Ctrl+Alt+F11";
+            require(mergeSyncProfile(base, bytes(l), bytes(r)).conflicts.size() == 2, "cross-field shortcut collisions exposed");
+            l = r = j; l["excludedApps"].push_back("local-app"); r["excludedApps"].push_back("remote-app");
+            require(parse(mergeSyncSettings(base, bytes(l), bytes(r)))["excludedApps"].size() == j["excludedApps"].size() + 2,
+                "independent exclusion edits merge");
+        }
+        FakeProvider provider;
+        rejects([&] { synchronize(provider, {}, base, SyncAction::Automatic); }, "empty server never auto-populated");
+        auto result = synchronize(provider, {}, base, SyncAction::Upload);
+        require(result.revision == 1 && provider.writes == 1, "initial upload CAS zero");
+        result = synchronize(provider, base, base, SyncAction::Automatic);
+        require(provider.writes == 1 && result.revision == 1, "no-op avoids versions");
+        result = synchronize(provider, base, bytes(left), SyncAction::Download);
+        require(parse(result.settings) == parse(base) && provider.writes == 1, "download never writes");
+        provider.race = true;
+        rejects([&] { synchronize(provider, base, bytes(left), SyncAction::Upload); }, "racing writer protected");
+        require(provider.writes == 1 && provider.remote.settings == base, "CAS failure preserves remote");
+        provider.race = false;
+        {
+            auto remoteProfile = j;
+            remoteProfile["layouts"] = Json::array({"win:00000422"});
+            remoteProfile["layoutHotkeys"] = Json::array({{{"layoutId", "win:00000422"}, {"hotkey", "Ctrl+Alt+9"}}});
+            remoteProfile["autoCorrectNever"].push_back("remoteword");
+            FakeProvider partial;
+            partial.remote = {3, bytes(remoteProfile)};
+            auto validate = [&](const Bytes &b) { restoreSyncSettings(b, local, {}, true); };
+            auto result = synchronize(partial, {}, base, SyncAction::Automatic, validate, {}, true);
+            auto restored = restoreSyncSettings(result.settings, local, {}, true);
+            require(restored.cycle == local.cycle && restored.direct == local.direct &&
+                    restored.autoNever == std::vector<std::wstring>{L"remoteword"},
+                    "partial sync restores other settings and keeps local layout configuration");
+            auto next = sharedSyncSettings(restored);
+            result = synchronize(partial, result.base, next, SyncAction::Automatic, validate, {}, true);
+            require(parse(partial.remote.settings)["layouts"] == remoteProfile["layouts"] &&
+                    parse(partial.remote.settings)["layoutHotkeys"] == remoteProfile["layoutHotkeys"],
+                    "repeated partial sync never deletes unavailable server layouts or shortcuts");
+            auto changed = parse(next); changed["autoCorrectMinLength"] = 7;
+            result = synchronize(partial, result.base, bytes(changed), SyncAction::Upload, validate, {}, true);
+            require(parse(partial.remote.settings)["autoCorrectMinLength"] == 7 &&
+                    parse(partial.remote.settings)["layoutHotkeys"] == remoteProfile["layoutHotkeys"],
+                    "explicit partial upload preserves server layouts too");
+            auto downloaded = synchronize(partial, result.base, base, SyncAction::Download, validate, {}, true);
+            auto downloadedSettings = restoreSyncSettings(downloaded.settings, local, {}, true);
+            require(downloadedSettings.autoMinLength == 7 && downloadedSettings.cycle == local.cycle &&
+                    downloadedSettings.direct == local.direct, "partial Download applies other settings without replacing local layouts");
+            try { restoreSyncSettings(bytes(remoteProfile), local, {}); require(false, "full sync must identify missing layouts"); }
+            catch (const std::runtime_error &e) {
+                std::string message = e.what();
+                require(message.find("win:00000422") != message.npos && message.find("Keep this PC's layouts") != message.npos,
+                        "missing-layout error identifies IDs and offers partial sync");
+            }
+        }
+        rejects([&] { synchronize(provider, base, bytes(left), SyncAction::Upload,
+            [](const Bytes &) { throw std::runtime_error("invalid"); }); }, "validate before upload");
+        require(provider.writes == 1, "invalid data not uploaded");
+        saveSyncBase(root, config, base);
+        require(parse(loadSyncBase(root, config)) == j, "encrypted baseline round trip");
+        auto other = config; other.path = L"other/settings";
+        require(loadSyncBase(root, other).empty(), "baseline bound to connection");
+        auto encrypted = readFile(root / L"sync-base.bin", 1024 * 1024);
+        std::string disk(encrypted.begin(), encrypted.end());
+        require(disk.find("private snippet") == disk.npos, "baseline encrypted on disk");
+        // Exercise real Credential Manager with an isolated test target, never a user endpoint.
+        config.username = L"ks-sync-test-" + std::to_wstring(GetCurrentProcessId());
+        saveSyncPassword(config, L"test-only-password");
+        int logins{}, revokes{}, reads{}, writes{};
+        unsigned readStatus = 200, writeStatus = 200;
+        bool deleted = false;
+        auto transport = [&](const std::wstring &method, const std::wstring &path,
+            const std::wstring &token, const Bytes &body) -> SyncHttpResponse {
+            if (path == L"/v1/auth/userpass/login/" + config.username)
+            {
+                require(method == L"POST" && token.empty(), "login route and no bearer token");
+                require(parse(body)["password"] == "test-only-password", "password sourced from credential manager");
+                ++logins;
+                return {200, bytes({{"auth", {{"client_token", "test-token"}}}})};
+            }
+            require(token == L"test-token", "authenticated requests use returned token");
+            if (path == L"/v1/auth/token/revoke-self")
+            {
+                require(method == L"POST", "revoke method"); ++revokes; return {204, {}};
+            }
+            require(path == L"/v1/kswitcher/data/personal/settings", "KV v2 data route");
+            if (method == L"GET")
+            {
+                ++reads;
+                if (readStatus != 200 && !deleted) return {readStatus, bytes({{"errors", Json::array()}})};
+                return {readStatus, bytes({{"data", {
+                    {"metadata", {{"version", 7}, {"deletion_time", deleted ? "2026-01-01" : ""}, {"destroyed", false}}},
+                    {"data", {{"syncSchema", 1}, {"settings", j}}}}}})};
+            }
+            require(method == L"POST", "write method");
+            auto request = parse(body);
+            require(request["options"]["cas"] == 7, "write includes exact CAS revision");
+            require(request["data"]["syncSchema"] == 2 && request["data"]["settings"] == j, "versioned settings envelope");
+            ++writes;
+            return {writeStatus, bytes({{"data", {{"version", 8}}}})};
+        };
+        {
+            auto bao = makeSyncProvider(config, transport);
+            auto doc = bao->read();
+            require(doc.revision == 7 && parse(doc.settings) == j, "read protocol response");
+            require(bao->write(base, 7) == 8, "write protocol response");
+            readStatus = 404;
+            require(bao->read().revision == 0, "missing profile");
+            deleted = true;
+            rejects([&] { bao->read(); }, "soft deleted is not treated as absent");
+            deleted = false; readStatus = 403;
+            rejects([&] { bao->read(); }, "permission denied is not absent");
+            readStatus = 302;
+            rejects([&] { bao->read(); }, "redirect response rejected");
+            writeStatus = 400;
+            rejects([&] { bao->write(base, 7); }, "server CAS refusal propagated");
+        }
+        require(logins == 1 && revokes == 1 && reads == 5 && writes == 2, "temporary login lifecycle");
+        forgetSyncPassword(config); forgetSyncPassword(config);
+        ++checks;
+        std::filesystem::remove_all(root);
+        std::cout << checks << " sync checks passed\n";
+        return 0;
+    }
+    catch (const std::exception &e)
+    {
+        std::cerr << e.what() << "\n";
+        return 1;
+    }
+}
@@ -4,6 +4,7 @@
 #include "richtext.h"
 #include "storage.h"
 #include "diagnostics.h"
+#include "json.hpp"
 #include <algorithm>
 #include <iostream>
 #include <map>
@@ -23,20 +24,6 @@ void rejects(const std::function<void()> &f, const char *name)
    bool thrown = false;
    try
    {
-        {
-            std::map<std::wstring,int> previews;
-            std::set<std::wstring> visible;
-            for(int i=0;i<40;++i) previews[std::to_wstring(i)]=i;
-            for(int i=0;i<8;++i) visible.insert(std::to_wstring(i));
-            ks::trimHistoryPreviews(previews,visible);
-            require(previews.size()==32,"preview cache stays bounded");
-            for(const auto &id:visible) require(previews.contains(id),"visible preview survives eviction");
-            for(int i=0;i<40;++i) { auto id=std::to_wstring(i); previews[id]=i; visible.insert(id); }
-            ks::trimHistoryPreviews(previews,visible);
-            require(previews.size()==40,"tall viewport does not thrash visible previews");
-            visible.clear(); ks::trimHistoryPreviews(previews,visible);
-            require(previews.size()==32,"cache shrinks after leaving tall viewport");
-        }
        f();
    }
    catch (...)
@@ -60,6 +47,34 @@ int main(int argc, char **argv)
    }
    try
    {
+        // Byte budgets must retain visible entries even when they alone exceed the budget.
+        {
+            std::map<std::wstring, size_t> cache{{L"a", 800}, {L"b", 800}, {L"c", 100}};
+            std::set<std::wstring> visible{L"b"};
+            auto weight=[](size_t bytes) { return bytes; };
+            ks::trimHistoryPreviews(cache, visible, 32, 1000, weight);
+            require(cache.size()==2 && cache.contains(L"b") && cache.contains(L"c"),
+                    "byte budget evicts offscreen previews below count limit");
+            ks::trimHistoryPreviews(cache, visible, 32, 100, weight);
+            require(cache.size()==1 && cache.contains(L"b"), "oversized visible preview never thrashes");
+            visible.clear();
+            ks::trimHistoryPreviews(cache, visible, 32, 100, weight);
+            require(cache.empty(), "oversized preview is freed after leaving viewport");
+        }
+        {
+            std::map<std::wstring,int> previews;
+            std::set<std::wstring> visible;
+            for(int i=0;i<40;++i) previews[std::to_wstring(i)]=i;
+            for(int i=0;i<8;++i) visible.insert(std::to_wstring(i));
+            ks::trimHistoryPreviews(previews,visible);
+            require(previews.size()==32,"preview cache stays bounded");
+            for(const auto &id:visible) require(previews.contains(id),"visible preview survives eviction");
+            for(int i=0;i<40;++i) { auto id=std::to_wstring(i); previews[id]=i; visible.insert(id); }
+            ks::trimHistoryPreviews(previews,visible);
+            require(previews.size()==40,"tall viewport does not thrash visible previews");
+            visible.clear(); ks::trimHistoryPreviews(previews,visible);
+            require(previews.size()==32,"cache shrinks after leaving tall viewport");
+        }
        {
            ks::DiagnosticJson record{{"attempt", "42"}, {"process", "editor.exe"}, {"command", "Convert / cycle"},
                {"source", "English"}, {"target", "Ukrainian"}, {"outcome", "Original text remained"},
@@ -99,6 +114,10 @@ int main(int argc, char **argv)
                "large diagnostic selections are explicitly truncated");
        STARTUPINFOW startup{sizeof(startup)};
        ks::DiagnosticBuffer diagnostics;
+        diagnostics.record(L"idle-expiry", false, 0);
+        require(diagnostics.expire(30000)==0,"diagnostics remain available at expiry boundary");
+        require(diagnostics.expire(30001)==1,"idle expiry releases context without another log event");
+        require(diagnostics.expire(60000)==0,"repeated idle expiry is safe");
        require(diagnostics.record(L"successful-attempt", false, 100).empty(),
                "successful diagnostics stay in memory");
        auto incident = diagnostics.record(L"failed-attempt", true, 200);
@@ -111,8 +130,8 @@ int main(int argc, char **argv)
        require(diagnostics.record(L"later-failure", true, 30500).find(L"expired-context") == std::wstring::npos,
                "context expires after thirty seconds");
        diagnostics.record(L"oldest-context", false, 30600);
-        for (int i = 0; i < 40; ++i)
-            diagnostics.record(L"bounded-context", false, 30600 + i);
+        for (int i = 0; i < 128; ++i)
+            diagnostics.record(L"bounded-context", false, 30600);
        require(diagnostics.record(L"bounded-failure", true, 30700).find(L"oldest-context") == std::wstring::npos,
                "context buffer has a fixed size");
        diagnostics.record(L"disabled-context", false, 30800);
@@ -171,6 +190,8 @@ int main(int argc, char **argv)
                "HTML entities and Unicode survive without script text");
        require((effects(0, 6) & CFE_BOLD) != 0, "inline CSS bold is rendered");
        auto plain = ks::textClip(L"{\\literal} Привіт");
+        require(ks::richPreview(plain, false).empty(), "plain history preview does not require RichEdit");
+        require(!ks::richPreview(styled, false).empty(), "formatted history preview retains HTML rendering");
        ks::setRichText(rich, ks::richPreview(plain));
        GetWindowTextW(rich, rendered, 256);
        require(std::wstring(rendered) == plain.text(), "plain Unicode and RTF metacharacters are escaped");
@@ -192,11 +213,58 @@ int main(int argc, char **argv)
        require(ks::convert(L"hello привет", en, ru) == L"руддщ привет", "mixed text preserves target words");
        require(ks::convert(L"htdm.dftim", en, ru) == L"ревьюваешь", "punctuation in words");
        std::vector<ks::Layout> layouts{en, ru, uk};
+        ks::Run suffixRun;
+        suffixRun.keys = L"snipping ";
+        require(suffixRun.matchSuffix(L"зштп ", layouts, en) >= 0,
+                "recent Cyrillic suffix matches physical keys across layouts");
+        require(suffixRun.matchSuffix(L"ping ", layouts, en) == 0,
+                "recent English suffix matches physical keys");
+        require(suffixRun.matchSuffix(L"other", layouts, en) < 0 &&
+                    suffixRun.matchSuffix(L"", layouts, en) < 0 &&
+                    suffixRun.matchSuffix(L"snipping ", layouts, en) < 0,
+                "suffix recovery rejects unrelated, empty and complete ranges");
+        suffixRun.overflow = true;
+        require(suffixRun.matchSuffix(L"зштп ", layouts, en) < 0,
+                "suffix recovery rejects overflowed tracking");
+        suffixRun.overflow = false;
+        suffixRun.keys = L"LinkedIn ";
+        require(suffixRun.matchSuffix(L"лувШт ", layouts, en) >= 0,
+                "ChatGPT partial CamelCase selection matches tracked physical suffix");
+        require(suffixRun.match(L"ДштлувШт ", layouts, en) >= 0 &&
+                    suffixRun.match(L"лувШт ", layouts, en) < 0,
+                "CamelCase conversion still requires the complete tracked text after recovery");
        ks::AutoCorrector corrector;
        ks::Settings autoSettings;
        require(!autoSettings.autoCorrect, "auto-correction defaults off");
        autoSettings.cycle = {L"en", L"uk"};
        corrector.configure(L"dictionaries", autoSettings.autoLanguages);
+        {
+            ks::AutoCorrector consumer;
+            consumer.shareDictionaries(corrector);
+            require(consumer.suggest(L"ghbdsn ", 0, layouts, autoSettings).has_value(),
+                    "shared dictionaries produce the same correction");
+            consumer.reject(L"ghbdsn");
+            consumer.shareDictionaries(corrector);
+            require(!consumer.suggest(L"ghbdsn ", 0, layouts, autoSettings),
+                    "refreshing shared dictionaries preserves consumer undo rejections");
+            require(corrector.suggest(L"ghbdsn ", 0, layouts, autoSettings).has_value(),
+                    "consumer rejections do not affect the predictor");
+            ks::AutoCorrector retained;
+            retained.shareDictionaries(corrector);
+            corrector.configure({}, {});
+            require(retained.suggest(L"ghbdsn ", 0, layouts, autoSettings).has_value(),
+                    "in-flight dictionary snapshot survives source reset");
+            consumer.shareDictionaries(corrector);
+            require(consumer.memoryBytes() == 0, "disabled correction releases consumer dictionaries");
+            corrector.shareDictionaries(retained);
+        }
+        {
+            auto options = autoSettings;
+            options.autoTypos = true;
+            auto typo = corrector.suggest(L"првиіт ", 2, layouts, options);
+            require(typo && typo->text == L"привіт " && typo->target == 2,
+                    "bundled Ukrainian dictionary corrects a common transposition");
+        }
        auto suggested = corrector.suggest(L"ghbdsn ", 0, layouts, autoSettings);
        require(suggested && suggested->text == L"привіт " && suggested->target == 2,
                "dictionary corrects Ukrainian and retains trailing space");
@@ -291,6 +359,14 @@ int main(int argc, char **argv)
            options.autoLanguages = {L"en", L"uk", L"ru"};
            options.cycle = {L"en", L"uk", L"ru"};
            supplemental.configure(L"dictionaries", options.autoLanguages);
+            auto current = supplemental.suggest(L"Gjnjxys ", 0, layouts, options);
+            require(current && current->text == L"Поточні " && current->target == 2,
+                    "reported title-case Ukrainian word corrects with all three dictionaries enabled");
+            current = supplemental.suggest(L"Поточны ", 1, layouts, options);
+            require(current && current->text == L"Поточні " && current->target == 2,
+                    "reported Ukrainian word corrects from Russian layout");
+            require(!supplemental.suggest(L"Поточні ", 2, layouts, options),
+                    "correct Ukrainian word remains unchanged");
            for (auto [typed, expected] : {std::pair{L"ntcn ", L"тест "}, std::pair{L"vfkj ", L"мало "}})
            {
                auto shared = supplemental.suggest(typed, 0, layouts, options);
@@ -307,6 +383,8 @@ int main(int argc, char **argv)
            require(!supplemental.suggest(L"релиз ", 1, layouts, options),
                    "valid Russian release word stays unchanged");
            options.autoMaxRank = 50000;
+            require(!supplemental.suggest(L"Gjnjxys ", 0, layouts, options),
+                    "supplemental current word respects explicit frequency limit");
            require(!supplemental.suggest(L"релыз ", 1, layouts, options),
                    "supplemental vocabulary respects explicit frequency limit");
            options.autoWords[L"uk"] = {L"релізик"};
@@ -337,6 +415,22 @@ int main(int argc, char **argv)
        require(ks::convertTo(L"ghbdtn", layouts, 1, 0) == L"привет", "hint conversion");
        require(ks::convertTo(L"привет", layouts, 1, 1) == L"привет", "same source is unchanged");
        require(ks::convertTo(L"?", layouts, 1, 0) == L",", "punctuation conversion");
+        require(ks::nextConversionLayout(L"рф", layouts, {0, 1, 2}, 1) == 0 &&
+                    ks::convertTo(L"рф", layouts, 0, 1) == L"ha",
+                "cycle skips unchanged Russian to Ukrainian and wraps to English");
+        require(ks::nextConversionLayout(L"шььш", layouts, {0, 2, 1}, 2) == 0 &&
+                    ks::convertTo(L"шььш", layouts, 0, 2) == L"immi",
+                "cycle skips unchanged Ukrainian to Russian");
+        require(ks::nextConversionLayout(L"і", layouts, {0, 2, 1}, 2) == 1,
+                "cycle keeps the next language when text changes");
+        require(ks::nextConversionLayout(L"ha", layouts, {0, 1, 2}, 0) == 1,
+                "cycle preserves configured order for changed text");
+        require(ks::nextConversionLayout(L"рф", layouts, {1, 2}, 1) == 2,
+                "cycle does not use disabled English when all candidates are unchanged");
+        require(ks::nextConversionLayout(L"123 ", layouts, {0, 1, 2}, 0) == 1,
+                "unchanged digits finish after a bounded cycle");
+        require(ks::nextConversionLayout(L"рф", layouts, {2, 0}, 1) == 0,
+                "source outside cycle still skips unchanged candidates");
        require(ks::cycleCase(L"hello world") == L"Hello World", "title case");
        require(ks::cycleCase(L"Hello World") == L"HELLO WORLD", "upper case");
        require(ks::cycleCase(L"ПРИВІТ") == L"привіт", "Unicode lower case");
@@ -423,6 +517,24 @@ int main(int argc, char **argv)
        auto encoded = ks::encodeClip(clip);
        require(ks::decodeClip(encoded).text() == clip.text(), "clipboard Unicode roundtrip");
        require(ks::decodeClip(encoded).formats[1].name == L"HTML Format", "registered format identity");
+        auto selection = ks::textClip(L";pa");
+        selection.formats.push_back({0, L"vscode-editor-data", {1, 2, 3}});
+        auto relayed = selection;
+        relayed.formats.front().data.resize(128, 0xab);
+        std::reverse(relayed.formats.begin(), relayed.formats.end());
+        require(ks::selectionClipboardIdentity(selection) == ks::selectionClipboardIdentity(relayed),
+                "clipboard relay tolerates Unicode allocation slack and format order");
+        relayed.formats.front().data[0] ^= 1;
+        require(ks::selectionClipboardIdentity(selection) != ks::selectionClipboardIdentity(relayed),
+                "clipboard relay rejects changed editor metadata");
+        relayed = selection;
+        relayed.formats.pop_back();
+        require(ks::selectionClipboardIdentity(selection) != ks::selectionClipboardIdentity(relayed),
+                "clipboard relay rejects missing editor metadata");
+        relayed = selection;
+        relayed.formats.front() = ks::textClip(L";pb").formats.front();
+        require(ks::selectionClipboardIdentity(selection) != ks::selectionClipboardIdentity(relayed),
+                "clipboard relay rejects changed Unicode text");
        auto encrypted = ks::protect(encoded);
        require(encrypted != encoded, "history ciphertext differs");
        require(ks::unprotect(encrypted) == encoded, "Windows DPAPI roundtrip");
@@ -451,8 +563,61 @@ int main(int argc, char **argv)
            auto correction = edited.suggest(L"руддщ ", 2, layouts, options);
            require(correction && correction->text == L"hello ",
                    "unsorted dictionaries and duplicates load using lowest duplicate rank");
+            require(!edited.suggest(L"hlelo ", 0, layouts, options), "spelling correction defaults off");
+            options.autoTypos = true;
+            for (auto typo : {L"hlelo ", L"helo ", L"helllo ", L"hezlo "})
+            {
+                correction = edited.suggest(typo, 0, layouts, options);
+                require(correction && correction->text == L"hello " && correction->target == 0,
+                        "single transposition, deletion, insertion and substitution retain the source layout");
+            }
+            correction = edited.suggest(L"(Hlelo), ", 0, layouts, options);
+            require(correction && correction->text == L"(Hello), ", "typos retain case and punctuation");
+            for (auto text : {L"hello ", L"HLELO ", L"hLelo ", L"h3llo ", L"h.llo ", L"hlo ", L"hello@example.com "})
+                require(!edited.suggest(text, 0, layouts, options), "known or unsafe typo input is unchanged");
+            options.autoWords[L"en"] = {L"hella"};
+            require(!edited.suggest(L"hell ", 0, layouts, options), "personal dictionary alternatives create ambiguity");
+            options.autoWords.clear();
+            options.autoReplacements = {{L"hlelo", L"greeting"}, {L"hello", L"greetings"}, {L"првиіт", L"привіт"}};
+            options.autoReplace = true;
+            correction = edited.suggest(L"Hlelo! ", 0, layouts, options);
+            require(correction && correction->text == L"Greeting! ", "explicit replacements override spelling guesses");
+            correction = edited.suggest(L"hello ", 0, layouts, options);
+            require(correction && correction->text == L"greetings ", "explicit replacements can override known words");
+            correction = edited.suggest(L"Првиіт ", 2, layouts, options);
+            require(correction && correction->text == L"Привіт " && correction->target == 2,
+                    "Ukrainian replacements work without dictionary membership");
+            options.autoNever = {L"hlelo"};
+            require(!edited.suggest(L"hlelo ", 0, layouts, options), "never-correct overrides explicit pairs");
+            options.autoNever.clear();
+            edited.reject(L"(Hlelo)! ", options);
+            require(!edited.suggest(L"hlelo ", 0, layouts, options), "undo rejection suppresses custom replacements");
+            options.autoReplace = false;
+            options.autoWords[L"uk"] = {L"привіт"};
+            correction = edited.suggest(L"првиіт ", 2, layouts, options);
+            require(correction && correction->text == L"привіт ", "Ukrainian personal words are typo targets");
+            options.cycle = {L"en"};
+            require(!edited.suggest(L"првиіт ", 2, layouts, options), "disabled source layouts do not correct typos");
+            put(L"en.txt", L"hello\t1\nhella\t99999\n");
+            ks::AutoCorrector ambiguous;
+            ambiguous.configure(folder, {L"en", L"uk"});
+            require(!ambiguous.suggest(L"hell ", 0, layouts, options), "frequency filter does not conceal ambiguous typo targets");
        }
        ks::Pixels pixels{2, 1, {10, 20, 30, 255, 40, 50, 60, 255}};
+        {
+            auto png = ks::encodePng(pixels);
+            ks::Clip encoded{{{0, L"PNG", png}}};
+            for (int i=0; i<3; ++i) {
+                auto decoded=ks::decodeImage(encoded);
+                require(decoded.bgra==pixels.bgra && decoded.width==2 && decoded.height==1,
+                        "borrowed PNG stream preserves decoded pixels on repeated reads");
+                require(encoded.formats[0].data==png,"PNG decoder never modifies the borrowed input");
+            }
+            ks::Clip fallback{{{0,L"PNG",{}},ks::imageDib(pixels)}};
+            require(ks::decodeImage(fallback).bgra==pixels.bgra,"empty PNG falls back to DIB");
+            ks::Clip invalid{{{0,L"PNG",{1,2,3}}}};
+            rejects([&] { ks::decodeImage(invalid); },"invalid borrowed PNG fails safely");
+        }
        ks::Clip firstImage{{ks::imageDib(pixels), {0, L"Ole Private Data", {1, 2, 3}}}};
        auto thumbnail = ks::decodeImage(firstImage, 1, 1);
        require(thumbnail.width == 1 && thumbnail.height == 1 && thumbnail.bgra.size() == 4,
@@ -491,11 +656,62 @@ int main(int argc, char **argv)
                    "Snipping Tool republish retains one pinned history entry");
            history.add(changedImage, L"SnippingTool", defaults);
            require(history.entries().size() == 2, "a new screenshot is retained");
+            auto copiedText = ks::textClip(L"text after screenshot");
+            history.add(copiedText, L"Editor", defaults);
+            history.add(copiedText, L"Editor", defaults);
+            require(history.entries().size() == 3 && !history.entries().front().image,
+                    "text after screenshot is retained and consecutive text duplicates are skipped");
+            history.add(changedImage, L"SnippingTool", defaults);
+            history.add(changedImage, L"SnippingTool", defaults);
+            require(history.entries().size() == 4 && history.entries().front().image,
+                    "image after text is retained and consecutive image duplicates are skipped");
+            history.add(withText, L"Editor", defaults);
+            require(history.entries().size() == 5,
+                    "mixed image and text payload is not discarded by metadata prefilter");
+        }
+        {
+            auto folder = temp / L"fingerprints";
+            ks::Settings defaults;
+            ks::History history(folder);
+            history.add(firstImage, L"test", defaults);
+            auto id = history.entries().front().id;
+            history.pin(id);
+            history.saveOcr(id, L"retained OCR", defaults);
+            ks::History reopened(folder);
+            require(reopened.entries().front().contentHash.size() == 64,
+                    "SHA-256 fingerprint survives encrypted index reload");
+            // Deny payload reads: duplicates must still be detected using only the index.
+            auto handle = CreateFileW((folder / (id + L".dat")).c_str(), GENERIC_READ, 0, nullptr,
+                                      OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, nullptr);
+            require(handle != INVALID_HANDLE_VALUE, "lock image payload for no-read regression");
+            reopened.add(firstImage, L"test", defaults);
+            reopened.add(secondImage, L"test", defaults);
+            reopened.add(recoded, L"test", defaults);
+            CloseHandle(handle);
+            require(reopened.entries().size() == 1 && reopened.entries().front().pinned &&
+                    reopened.ocrText(id) == std::optional<std::wstring>(L"retained OCR"),
+                    "exact, OLE and pixel-equivalent duplicates need no payload read and retain pin/OCR");
+            auto index = nlohmann::json::parse(ks::unprotect(ks::readFile(folder / L"index.dat", 1024*1024)));
+            for (auto &entry : index)
+                for (auto key : {"fingerprintVersion", "contentHash", "imageHash", "pixelHash"}) entry.erase(key);
+            auto legacy = index.dump();
+            ks::atomicWrite(folder / L"index.dat", ks::protect(ks::Bytes(legacy.begin(), legacy.end())));
+            ks::History migrated(folder);
+            migrated.add(secondImage, L"test", defaults);
+            ks::History persisted(folder);
+            require(persisted.entries().size() == 1 && persisted.entries().front().contentHash.size() == 64,
+                    "legacy duplicate migrates fingerprints without adding or losing an entry");
+            persisted.add(changedImage, L"test", defaults);
+            require(persisted.entries().size() == 2, "pixel fingerprint preserves genuinely changed images");
+            persisted.add(firstImage, L"test", defaults);
+            require(persisted.entries().size() == 3, "hash deduplication remains consecutive rather than global");
        }
        ks::Settings settings;
        settings.writeLog = false;
        settings.elevatedAutostart = true;
        settings.autoCorrect = true;
+        settings.autoReplace = settings.autoTypos = true;
+        settings.autoReplacements = {{L"првиіт", L"привіт"}, {L"helo", L"hello"}};
        settings.autoMaxRank = 10000;
        settings.autoMinLength = 5;
        settings.autoPrefixChars = L"(#";
@@ -508,6 +724,14 @@ int main(int argc, char **argv)
        ks::saveSettings(temp / L"settings.json", settings);
        auto restored = ks::loadSettings(temp / L"settings.json", {});
        require(restored.autoWords == settings.autoWords, "personal dictionaries survive settings roundtrip");
+        require(restored.autoReplace && restored.autoTypos && restored.autoReplacements == settings.autoReplacements,
+                "typo options and Unicode pairs survive settings roundtrip");
+        for (const auto &pair : {std::pair{L"hello", L"привіт"}, {L"hello", L"hello"}, {L"hi!", L"hello"}})
+        {
+            auto invalid = settings;
+            invalid.autoReplacements = {{pair.first, pair.second}};
+            rejects([&] { ks::validateSettings(invalid); }, "invalid replacement pairs rejected");
+        }
        auto invalidWords = settings;
        invalidWords.autoWords[L"uk"] = {L"hello"};
        rejects([&] { ks::validateSettings(invalidWords); }, "personal dictionary rejects wrong language letters");
@@ -4,7 +4,7 @@ import urllib.request, hashlib, json
 ROOT=Path(__file__).resolve().parents[1]/'dictionaries'
 REV='525f9b560de45753a5ea01069454e72e9aa541c6'
 # Supplemental vocabulary has no corpus frequency: rank after the 50k source list.
-SUPPLEMENTAL={'uk': {'реліз': 50001}}
+SUPPLEMENTAL={'uk': {'реліз': 50001, 'поточні': 50001}}
 ROOT.mkdir(exist_ok=True)
 manifest={}
 for lang in ('en','uk','ru'):
@@ -0,0 +1,61 @@
+param([ValidateRange(1,20)][int]$Runs=3,[ValidateRange(100,10000)][int]$SettleMilliseconds=1500)
+# Private resident pages are counted externally, so the measurement buffer is
+# allocated in PowerShell, not in the measured process. Never trim working sets.
+$ErrorActionPreference='Stop'
+$root=Split-Path $PSScriptRoot -Parent
+$output=Join-Path $root 'build/memory-components'
+New-Item -ItemType Directory -Force $output | Out-Null
+$exe=Join-Path $output 'probe.exe'
+& "$root/.tools/w64devkit/bin/g++.exe" -std=c++20 -Os -static -s -DUNICODE -D_UNICODE -D_WIN32_WINNT=0x0A00 "$PSScriptRoot/memory-components.cpp" -o $exe -lole32 -loleaut32 -lshell32 -lpropsys -lshlwapi -luuid -luiautomationcore
+if($LASTEXITCODE) { throw 'Probe compilation failed' }
+Add-Type @'
+using System;
+using System.Runtime.InteropServices;
+public static class ComponentWorkingSet {
+ [DllImport("psapi.dll", SetLastError=true)] static extern bool QueryWorkingSet(IntPtr process,IntPtr buffer,int size);
+ public static long PrivateBytes(IntPtr process) {
+  int size=4*1024*1024;
+  IntPtr buffer=Marshal.AllocHGlobal(size);
+  try {
+   if(!QueryWorkingSet(process,buffer,size)) throw new System.ComponentModel.Win32Exception();
+   long count=Marshal.ReadIntPtr(buffer).ToInt64(), pages=0;
+   if(count>(size/IntPtr.Size)-1) throw new InvalidOperationException("Working set buffer is too small");
+   for(int i=0;i<count;i++) if((Marshal.ReadIntPtr(buffer,(i+1)*IntPtr.Size).ToInt64() & 256)==0) pages++;
+   return pages*Environment.SystemPageSize;
+  } finally { Marshal.FreeHGlobal(buffer); }
+ }
+}
+'@
+$rows=[Collections.Generic.List[object]]::new()
+foreach($run in 1..$Runs) {
+ foreach($mode in @('baseline','sta','mta','shell','uia','focused','combined')) {
+  $start=[Diagnostics.ProcessStartInfo]::new($exe,$mode)
+  $start.UseShellExecute=$false; $start.CreateNoWindow=$true
+  $start.RedirectStandardOutput=$true; $start.RedirectStandardInput=$true; $start.RedirectStandardError=$true
+  $process=[Diagnostics.Process]::Start($start)
+  $errors=$process.StandardError.ReadToEndAsync()
+  try {
+   foreach($expected in @('baseline','com','active','released','uninitialized')) {
+    $pending=$process.StandardOutput.ReadLineAsync()
+    if(!$pending.Wait(15000)) { throw "Timeout: $mode/$expected" }
+    $phase=$pending.Result
+    if($phase -ne $expected) { throw "Unexpected phase '$phase', expected $expected" }
+    Start-Sleep -Milliseconds $SettleMilliseconds
+    $process.Refresh()
+    $rows.Add([pscustomobject]@{Run=$run;Mode=$mode;Phase=$phase;PrivateBytes=$process.PrivateMemorySize64;PrivateWorkingSet=[ComponentWorkingSet]::PrivateBytes($process.Handle);WorkingSet=$process.WorkingSet64;Threads=$process.Threads.Count;Modules=@($process.Modules | ForEach-Object ModuleName)})
+    $process.StandardInput.Write("`n"); $process.StandardInput.Flush()
+   }
+   if(!$process.WaitForExit(15000)) { throw 'Exit timeout' }
+   if($process.ExitCode) { throw "Probe failed: $($errors.Result)" }
+   $errors.Result | Set-Content (Join-Path $output "$run-$mode.txt")
+  } finally {
+   if(!$process.HasExited) { $process.Kill(); $process.WaitForExit() }
+   $process.Dispose()
+   $rows | ConvertTo-Json -Depth 5 | Set-Content (Join-Path $output 'results.json')
+  }
+  Write-Host "Completed $run/$Runs $mode"
+ }
+}
+$rows | Group-Object Mode,Phase | ForEach-Object {
+ [pscustomobject]@{Case=$_.Name;PrivateMiB=[math]::Round(($_.Group.PrivateBytes | Measure-Object -Average).Average/1MB,3);PrivateWorkingSetMiB=[math]::Round(($_.Group.PrivateWorkingSet | Measure-Object -Average).Average/1MB,3)}
+} | Format-Table
@@ -0,0 +1,65 @@
+// Standalone attribution probe. No clipboard, registry or user input mutations.
+#include <windows.h>
+#include <shlobj.h>
+#include <propkey.h>
+#include <propvarutil.h>
+#include <uiautomation.h>
+#include <cstdio>
+#include <cstring>
+#include <cstdlib>
+
+static void check(HRESULT hr) {
+    if (FAILED(hr)) { fprintf(stderr,"HRESULT=%08lx\n",(unsigned long)hr); exit(2); }
+}
+static void phase(const char *name) {
+    printf("%s\n",name); fflush(stdout);
+    if (getchar()==EOF) exit(3);
+}
+int main(int argc,char **argv) {
+    const char *mode=argc>1?argv[1]:"baseline";
+    const bool baseline=!strcmp(mode,"baseline");
+    const bool shell=!strcmp(mode,"shell") || !strcmp(mode,"combined");
+    const bool uia=!strcmp(mode,"uia") || !strcmp(mode,"focused") || !strcmp(mode,"combined");
+    phase("baseline");
+    if(!baseline) check(CoInitializeEx(nullptr,!strcmp(mode,"sta") || shell ? COINIT_APARTMENTTHREADED : COINIT_MULTITHREADED));
+    phase("com");
+    IShellLinkW *link{}; IPropertyStore *store{}; IPersistFile *file{};
+    IUIAutomation2 *automation{}; IUIAutomationElement *element{}; IUIAutomationTextPattern *pattern{};
+    wchar_t temporary[MAX_PATH]{},shortcut[MAX_PATH]{},exe[MAX_PATH]{};
+    if(shell) {
+        check(CoCreateInstance(CLSID_ShellLink,nullptr,CLSCTX_INPROC_SERVER,IID_PPV_ARGS(&link)));
+        GetModuleFileNameW(nullptr,exe,MAX_PATH);
+        check(link->SetPath(exe)); check(link->SetIconLocation(exe,0));
+        check(link->QueryInterface(IID_PPV_ARGS(&store)));
+        PROPVARIANT value{}; check(InitPropVariantFromString(L"KSwitcher.MemoryProbe",&value));
+        check(store->SetValue(PKEY_AppUserModel_ID,value)); PropVariantClear(&value);
+        GUID id{0xe3f78047,0xf0ad,0x49b6,{0x90,0x74,0x41,0x19,0x31,0x70,0x61,0x67}};
+        value.vt=VT_CLSID; value.puuid=&id;
+        check(store->SetValue(PKEY_AppUserModel_ToastActivatorCLSID,value)); check(store->Commit());
+        PWSTR programs{}; check(SHGetKnownFolderPath(FOLDERID_Programs,0,nullptr,&programs)); CoTaskMemFree(programs);
+        GetTempPathW(MAX_PATH,temporary); if(!GetTempFileNameW(temporary,L"ksm",0,shortcut)) return 4;
+        check(link->QueryInterface(IID_PPV_ARGS(&file))); check(file->Save(shortcut,TRUE));
+    }
+    if(uia) {
+        check(CoCreateInstance(CLSID_CUIAutomation8,nullptr,CLSCTX_INPROC_SERVER,IID_PPV_ARGS(&automation)));
+        check(automation->put_ConnectionTimeout(200)); check(automation->put_TransactionTimeout(200));
+        if(strcmp(mode,"uia")) {
+            HRESULT focused=automation->GetFocusedElement(&element);
+            fprintf(stderr,"focus=%08lx\n",(unsigned long)focused);
+            if(SUCCEEDED(focused) && element) {
+                BOOL password=TRUE,enabled=FALSE; CONTROLTYPEID type{};
+                element->get_CurrentIsPassword(&password); element->get_CurrentIsEnabled(&enabled); element->get_CurrentControlType(&type);
+                fprintf(stderr,"type=%d enabled=%d protected=%d\n",type,enabled,password);
+                if(!password) fprintf(stderr,"pattern=%08lx\n",(unsigned long)element->GetCurrentPatternAs(UIA_TextPatternId,IID_PPV_ARGS(&pattern)));
+            }
+        }
+    }
+    phase("active");
+    if(pattern) pattern->Release(); if(element) element->Release(); if(automation) automation->Release();
+    if(file) file->Release(); if(store) store->Release(); if(link) link->Release();
+    if(shortcut[0]) DeleteFileW(shortcut);
+    phase("released");
+    if(!baseline) { CoFreeUnusedLibrariesEx(0,0); CoUninitialize(); }
+    phase("uninitialized");
+    return 0;
+}
Author	SHA1	Message	Date
agrynco	6621a49022	Release v0.6.43: fix forwarded input and verify snippet pastes	2026-11-04 21:18:39 +02:00
agrynco	a2b88f247c	Release v0.6.42: use compact pinned checkbox beside history search	2026-11-04 20:38:36 +02:00
agrynco	684ca1b3cc	Release v0.6.41: filter and remember pinned clipboard history	2026-11-04 19:58:15 +02:00
agrynco	524a836cc0	Release v0.6.40: align tagged source and Windows version metadata	2026-11-04 19:45:52 +02:00
agrynco	00c9cb0ee4	Release v0.6.39: isolate history UI and image clipboard memory	2026-11-04 19:40:54 +02:00
agrynco	fa2f6d2ce4	Release v0.6.38: avoid unnecessary RichEdit and cancel hidden history previews	2026-11-04 17:24:57 +02:00
agrynco	30e70192dc	Release v0.6.37: isolate image capture and OCR, fingerprint history duplicates	2026-11-04 16:58:34 +02:00
agrynco	94cab4c112	Release v0.6.36: offload notification registration and mitigate Viber paste timing	2026-11-04 15:40:50 +02:00
agrynco	d13e9849a7	Release v0.6.35: reduce resident memory and compact shared dictionaries	2026-11-04 14:08:05 +02:00
agrynco	004fee4976	Release v0.6.34: use four-direction cursors for movable screenshot handles	2026-11-04 01:43:49 +02:00
agrynco	b08c5ff8ff	Release v0.6.33: warn about unsaved settings and expose menu access keys	2026-11-04 01:11:15 +02:00
agrynco	b6e7bda220	Release v0.6.32: make screenshot pan test independent of viewport DPI	2026-11-03 15:34:23 +02:00
agrynco	89e506faae	Release v0.6.31: verify trailing spaces omitted by editor copy	2026-11-03 14:45:35 +02:00
agrynco	c78b51d341	Record completed v0.6.30 release validation	2026-11-02 11:57:19 +02:00
agrynco	0184b837f4	Release v0.6.30: guard paste retries and clear failed conversion state	2026-11-02 11:54:58 +02:00
agrynco	ca553a5e7d	Release v0.6.29: clear clipboard history from its window	2026-11-02 11:34:45 +02:00
agrynco	55993c0f90	Release v0.6.28: typo correction, partial sync and selection diagnostics	2026-11-02 11:19:13 +02:00
agrynco	738c81dce2	Release v0.6.27: menu and Alt access keys	2026-11-02 01:23:33 +02:00
agrynco	22edece7cf	Release v0.6.26: OpenBao settings synchronization with per-setting conflicts	2026-11-02 00:37:57 +02:00
agrynco	908985d775	Release v0.6.25: recognize pencil strokes as straight lines	2026-11-01 23:00:59 +02:00
agrynco	20f3b72287	Release v0.6.24: smart shapes, rotation and canvas zoom	2026-11-01 22:25:15 +02:00
agrynco	9b231146cb	Release v0.6.23: improve browser selection, Ukrainian correction and PNG saving	2026-11-01 13:39:37 +02:00
agrynco	c0ab02df16	Release v0.6.22: recover verified partial text selections	2026-10-31 12:32:26 +02:00
agrynco	64a04b4382	Release v0.6.21: skip unchanged layouts during conversion	2026-10-31 11:39:19 +02:00
agrynco	4c5275631c	Remove development and scrolling internals from README	2026-10-31 09:17:38 +02:00
agrynco	34e07e7107	Keep public release documentation focused on image editing	2026-10-31 09:17:17 +02:00