Release v0.6.18: verify conversion results and log problems only

2026-10-31 01:36:56 +02:00
parent 4eb9f6c671
commit 0d3b2acae9
18 changed files with 915 additions and 291 deletions
@@ -0,0 +1,35 @@
+# Project instructions
+
+## Mandatory Wiki updates for every release
+
+A release is not complete until the published project Wiki reflects that release.
+Apply this rule to every release, including patch releases and bug-fix-only releases.
+
+Wiki: https://gitea.hrynco.com/hrynco/hrynco-kswitcher/wiki
+
+1. Confirm the release version from `CMakeLists.txt`, the release tag and
+   `Release/README.md`. Use the complete version (for example, `v0.6.17`) and
+   preserve the release channel rules in `README.md`.
+2. Update the latest-version information on the Wiki home pages and any other
+   pages identifying the current release. Update release dates, download links
+   and upgrade instructions where needed. Keep historical version references
+   and compatibility bridge instructions when they are still accurate.
+3. Review the changes since the last release documented in the Wiki, not just
+   the immediately preceding release. Bring the relevant feature pages up to
+   date with the shipped behavior: new, changed and removed functionality,
+   settings, shortcuts, defaults, limitations and troubleshooting. Update
+   screenshots or examples when they no longer match the application.
+   For bug-fix-only releases, check whether documented behavior or workarounds
+   need correction; do not invent feature changes.
+4. Keep English and Ukrainian pages synchronized, including `Home` and
+   `Home-uk`, and preserve working translation and navigation links.
+5. Publish the Wiki changes as part of the release workflow. Read back the
+   published pages and verify the current version, feature descriptions,
+   download links and translation links. A local Wiki edit alone is not enough.
+6. In the release completion report, link the updated Wiki pages and summarize
+   the documentation changes. If Wiki publication or verification is blocked,
+   explicitly report the outstanding step and do not claim the release workflow
+   is complete.
+
+Updating only the release notes or changing only the Wiki version number does
+not satisfy this rule; the current functionality must also be reviewed.
@@ -1,5 +1,5 @@
 cmake_minimum_required(VERSION 3.24)
-project(KSwitcher VERSION 0.6.17 LANGUAGES CXX RC)
+project(KSwitcher VERSION 0.6.18 LANGUAGES CXX RC)
 if(NOT WIN32)
  message(FATAL_ERROR "KSwitcher uses native Windows APIs")
 endif()
@@ -282,27 +282,38 @@ 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.
-Successful operations stay in a memory buffer of at most 40 diagnostic events for 30 seconds.
-Only failures flush this context to `kswitcher.log`; flushed
-context is discarded. Ordinary application errors are also logged when logging is enabled.
+Diagnostic stages stay in a memory buffer of at most 40 events for 30 seconds.
+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
+errors are also logged when logging is enabled. This works in normal Release builds.
 Incident context contains tracked physical input, the expected word, copied text, conversion result,
 and layout IDs, correlated by request ID even when verification fails. Text fields use quoted,
 escaped UTF-16 (`\uXXXX` for non-ASCII and control characters) for exact reproduction, with
-original length and a truncation flag; each field is limited to 512 UTF-16 code units.
+original length and a truncation flag; context fields are limited to 512 UTF-16 code units.
+Structured summaries retain up to 4096 UTF-16 code units per text field and mark truncation.
 Manual conversion attempts in `kswitcher.log` have request IDs and explicit outcomes, including
 busy, empty copy, verification mismatch, unchanged conversion, and cancelled paste. Requests
 record the process, window, input version, and repeated attempts within ten seconds without new
-input. Successful repeated commands do not flush the log; intentional layout cycling is normal.
-An unchanged result containing no letters, or a direct command
-to the detected current layout, is treated as expected. `paste-sent-unverified` means Windows
-accepted the paste shortcut; it does not prove that the editor applied the replacement.
+input. An unchanged manual conversion is recorded as a problem even when the detected source
+and target layouts coincide. After a changed result is pasted, read-only Windows Accessibility
+checks the focused editor without moving the caret, changing selection, or copying again.
+The log distinguishes **Paste verified**, **Original text remained**, **Readback differs**, and
+**Paste not verified**. Unsupported/protected controls, changed focus, and readback limits are
+explicit verification reasons, never proof of success. Readback is bounded to 4096 characters;
+provider-specific character units or delayed editor updates may prevent verification.
+With logging disabled, this additional accessibility check is skipped.
 The previous 256 KiB log is retained as `kswitcher.log.1` when the current log rotates.
 Open **View log…** from Settings or the tray menu to read logs inside KSwitcher.
 The viewer runs in the configurator process so log loading, painting and pointer interaction do not
 block the resident keyboard/mouse hook thread. Clear requests are still serialized by the resident.
 Choose the current or previous log and press **Refresh** to reload. The ListView shows Time,
-Attempt, Event, and Details columns. Select rows and use **Copy selected** or Ctrl+C to copy
-tab-separated entries; Ctrl+A selects all rows. Viewing saved logs also works when logging is disabled.
+Program, Command, Source layout, Target layout, and Result. Click column headings to sort;
+filter by program, command, or result, or enable **Only problems**. **Reset filters** restores all entries.
+Select a row to inspect original, expected and read-back text, verification status and stages
+in the panel below. **Copy selected** or Ctrl+C copies the selected rows with their details;
+Ctrl+A selects all rows. Older unstructured log entries remain readable. Viewing saved logs
+also works when logging is disabled.
 **Clear log** clears only the selected current or previous file and refreshes the table.
 Clearing the current log also discards buffered diagnostic context; new problems can still be logged.

@@ -454,6 +465,13 @@ against a staged build. It briefly opens real selection/editor windows without c

 ### Release channel rule

+Every release must also update the published [Wiki](https://gitea.hrynco.com/hrynco/hrynco-kswitcher/wiki):
+the latest version and relevant feature documentation in both English and Ukrainian.
+Review all changes since the last documented release, update affected instructions,
+shortcuts, settings and screenshots, and verify the published pages and links.
+The release workflow is incomplete until this is done. Follow the mandatory
+[Wiki release checklist](AGENTS.md#mandatory-wiki-updates-for-every-release).
+
 Keep `v0.4.2` as the last legacy `vX.Y.Z` release. Publish full packages as
 `release-vX.Y.Z` (stable, not prerelease), including `release-files.json`,
 `KSwitcher-win-x64.zip` and `SHA256SUMS.txt`. Never publish a manifest package under a
@@ -1,15 +1,18 @@
 # Latest Windows release

-## v0.6.17 — 2026-10-30
+## v0.6.18 — 2026-10-31

 ## Changes
- Hold Shift with the screenshot pencil to draw horizontal, vertical or 45-degree diagonal segments. Release Shift to continue freehand within the same stroke.
- Move more than 50 image pixels away from the active line to change direction while preserving earlier segments. Smooth diagonal gestures use the actual mouse trajectory instead of producing stair steps.
- Keep diagonal strokes inside image boundaries without changing their angle. Ctrl retains its existing draw-over-objects behavior; undo/redo treats the complete stroke as one object.
- Disable snippet fields, Delete and marker insertion until a snippet is selected or added. Deleting the selected snippet clears and disables the editor.
+- Verify the actual editor text after manual conversion using read-only Windows Accessibility, without moving the caret, changing selection or copying again. Record unchanged calculations, original text remaining, unexpected readback and unavailable verification separately.
+- Replace the event-only diagnostic list with sortable Time, Program, Command, Source layout, Target layout and Result columns; add program/command/result filters and a separate panel with original, expected and read-back text and operation context.
+- Keep successful operations only in a bounded in-memory context (40 events, 30 seconds). Only problem operations create file rows; verified successes do not fill the log. Diagnostics work in normal Release builds and the additional readback check is skipped when logging is disabled.
+- Refresh English and Ukrainian Wiki documentation through v0.6.18, including previously undocumented snippet, updater and constrained-pencil changes since v0.6.14.
+
+## Limitations
+Some editors do not expose their text through Windows Accessibility. Changed focus, protected or unsupported controls, provider-specific character units, delayed text updates and the 4096-character readback limit can prevent verification; these cases are recorded as unverified rather than successful. Historical unstructured entries remain readable without retroactive filter fields.

 ## Validation
-Passed 223 native regression checks, 472 input/UI checks, screenshot editor UI and notification registration checks, 48 updater checks, updater progress checks, and 45 isolated configurator process checks. Screenshot UI coverage includes smooth diagonal gestures in all four directions, direction changes, image boundaries, Shift transitions, Ctrl behavior and undo/redo. Configurator checks cover disabled snippet editing, Add, Delete, reselection and preservation of snippet content.
+Passed 230 native regression checks, 472 input/UI checks, screenshot editor UI and notification registration checks, 48 updater checks, updater progress checks, 45 isolated configurator process checks, conversion-specific editor integration and diagnostic viewer checks. Verified that 1000 successful operations create no log file and that a subsequent failure creates one row with bounded context. The broader editor integration suite still intermittently fails in snippet Enter/concurrent-input scenarios; similar failures reproduce with the pre-change code.

 **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 and extract the entire ZIP into its installation folder. Keep personal `data/` and customized dictionaries.
@@ -1 +1 @@
-d5813a42105a2aebb5b6ef414c0546a44f18e4d7f3d45e0f32830097781b9677  KSwitcher-win-x64.zip
+3e76d8a566c623a3084c00cc909f4cc7c8a6edb38f9c06adbb32edfd4cfcb5b7  KSwitcher-win-x64.zip
@@ -9,8 +9,8 @@ IDC_SCREENSHOT_PENCIL CURSOR "icons/lucide/pencil.cur"
 1 RT_MANIFEST "app.manifest"
 201 RCDATA "update.ps1"
 1 VERSIONINFO
- FILEVERSION 0,6,17,0
- PRODUCTVERSION 0,6,17,0
+ FILEVERSION 0,6,18,0
+ PRODUCTVERSION 0,6,18,0
 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", "0.6.17"
+   VALUE "FileVersion", "0.6.18"
  END
 END
 BLOCK "VarFileInfo"
@@ -2,6 +2,8 @@
 #include "../resources/resource.h"
 #include "ocr.h"
 #include "configuration.h"
+#include "diagnostics.h"
+#include "paste_probe.h"
 #include "screenshot_notifications.h"
 #include <algorithm>
 #include <commctrl.h>
@@ -12,6 +14,12 @@ namespace ks
 App *App::current = nullptr;
 namespace
 {
+const char *transformCommandName(int command)
+{
+    return command == Toggle ? "Convert / cycle" : command >= Direct ? "Convert / direct" :
+        command == Case ? "Change case" : command == Translit ? "Transliterate" :
+        command == Undo ? "Undo" : "Automatic / snippet";
+}
 ULONG_PTR snippetReplayMarker()
 {
    static const char marker{};
@@ -854,7 +862,18 @@ void App::transform(int command, int snippet)
    if (busy.exchange(true) && !preDeferred)
    {
        if (manual)
-            diagnosticEvent(L"Transform outcome id=" + std::to_wstring(attempt) + L" reason=busy", true);
+        {
+            diagnosticEvent(L"Transform outcome id=" + std::to_wstring(attempt) + L" reason=busy");
+            try
+            {
+                DiagnosticJson record{{"attempt", std::to_string(attempt)}, {"process", utf8(processName(target))},
+                    {"command", transformCommandName(command)}, {"source", "Unknown"}, {"target", "Unknown"},
+                    {"outcome", "busy"}, {"verification", "not-attempted"}, {"problem", true},
+                    {"elapsedMs", GetTickCount64() - requestedAt}};
+                diagnosticOperation(record.dump());
+            }
+            catch (...) {}
+        }
        return;
    }
    if (preDeferred)
@@ -893,7 +912,7 @@ void App::transform(int command, int snippet)
            } reset{busy, window, preDeferred};
            auto start = GetTickCount64();
            std::wstring reason = L"cancelled-before-selection";
-            std::wstring text, result, expected;
+            std::wstring text, result, expected, actual, verification = L"not-attempted";
            int hint = -1, to = command >= Direct ? command - Direct : -1;
            if (manual)
            {
@@ -918,21 +937,34 @@ void App::transform(int command, int snippet)
                bool enabled;
                std::wstring &reason;
                std::wstring &text, &result, &expected;
+                std::wstring &actual, &verification;
                int &hint, &to;
+                int command;
+                const std::vector<Layout> &layouts;
                ~Audit()
                {
                    if (enabled)
-                        diagnosticEvent(L"Transform outcome id=" + std::to_wstring(attempt) + L" reason=" + reason +
-                            L" foregroundSame=" + std::to_wstring(GetForegroundWindow() == target) +
-                            L" inputSame=" + std::to_wstring(app.inputVersion.load() == version) +
-                            L" elapsedMs=" + std::to_wstring(GetTickCount64() - start) +
-                            L" source=" + std::to_wstring(hint) + L" target=" + std::to_wstring(to) +
-                            L" expected=" + diagnosticText(expected) + L" copied=" + diagnosticText(text) +
-                            L" result=" + diagnosticText(result),
-                            reason != L"paste-sent-unverified" && reason != L"layout-only" &&
-                            reason != L"unchanged-expected");
+                        try
+                        {
+                            auto layout = [&](int index) { return index >= 0 && index < (int)layouts.size()
+                                ? utf8(layouts[index].name + L" (" + layouts[index].id + L")") : std::string("Unknown"); };
+                            auto bounded = [](const std::wstring &value) { return utf8(value.substr(0, 4096)); };
+                            DiagnosticJson record{{"attempt", std::to_string(attempt)}, {"process", utf8(processName(target))},
+                                {"command", transformCommandName(command)}, {"source", layout(text.empty() ? hint : detect(text, layouts, hint))}, {"target", layout(to)},
+                                {"outcome", utf8(reason)}, {"verification", utf8(verification)},
+                                {"problem", reason != L"Paste verified" && reason != L"layout-only" &&
+                                    !(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}};
+                            diagnosticOperation(record.dump(-1, ' ', true, DiagnosticJson::error_handler_t::replace));
                        }
-            } audit{*this, target, version, attempt, requestedAt, manual || snippet >= 0, reason, text, result, expected, hint, to};
+                        catch (...) {} // Logging must never abort a completed input transaction.
+                }
+            } audit{*this, target, version, attempt, requestedAt, manual || snippet >= 0, reason, text, result, expected,
+                    actual, verification, hint, to, command, available};
            try
            {
                auto valid = [&]
@@ -1157,6 +1189,7 @@ void App::transform(int command, int snippet)
                    }
                }
                bool sent = false;
+                PasteProbe probe(config.writeLog && manual && result != text, text);
                diagnosticEvent(L"Conversion source=" + std::to_wstring(hint) + L" target=" + std::to_wstring(to) +
                    L" changed=" + std::to_wstring(result != text));
                if (result != text)
@@ -1167,10 +1200,27 @@ void App::transform(int command, int snippet)
                    autoSelected = false;
                reason = result == text ? L"conversion-unchanged" :
                         sent ? L"paste-sent-unverified" : L"paste-cancelled";
-                if (result == text &&
-                    (std::none_of(text.begin(), text.end(), letter) ||
-                     (command >= Direct && detect(text, available, hint) == to)))
-                    reason = L"unchanged-expected";
+                if (manual && result == text)
+                {
+                    reason = L"Conversion unchanged";
+                    verification = L"calculated-result-equals-original";
+                }
+                if (sent && manual && config.writeLog)
+                {
+                    verification = probe.status;
+                    if (tx.valid())
+                    {
+                        auto observed = probe.read((int)caretSteps(result));
+                        verification = probe.status;
+                        if (observed && tx.valid())
+                        {
+                            actual = *observed;
+                            reason = conversionReadbackOutcome(newlines(actual), newlines(text), newlines(result));
+                        }
+                        else reason = L"Paste not verified";
+                    }
+                    else verification = L"context-changed-after-paste";
+                }
                if (sent && !tx.valid())
                    reason = L"context-changed-after-paste";
                if (sent && command == Undo && previous && previous->autoCorrected)
@@ -0,0 +1,76 @@
+#pragma once
+#include "../vendor/json.hpp"
+#include "platform.h"
+#include <sstream>
+
+namespace ks
+{
+using DiagnosticJson = nlohmann::json;
+struct OperationLogRow
+{
+    std::wstring time, process, command, source, target, outcome, details;
+    bool problem = true;
+};
+inline std::vector<OperationLogRow> parseOperationLog(const std::wstring &contents)
+{
+    std::vector<OperationLogRow> rows;
+    std::wistringstream stream(contents);
+    std::wstring line;
+    OperationLogRow *legacy = nullptr;
+    while (std::getline(stream, line))
+    {
+        if (!line.empty() && line.back() == L'\r')
+            line.pop_back();
+        if (line.empty())
+            continue;
+        auto marker = line.find(L" Operation {");
+        if (marker != line.npos)
+        {
+            try
+            {
+                auto j = DiagnosticJson::parse(utf8(line.substr(marker + 11)));
+                auto field = [&](const char *key) { return wide(j.value(key, std::string{})); };
+                OperationLogRow row{line.substr(0, marker), field("process"), field("command"),
+                                    field("source"),        field("target"),  field("outcome")};
+                row.problem = j.value("problem", true);
+                row.details =
+                    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") +
+                    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: " +
+                    (j.value("textTruncated", false) ? L"yes (4096 UTF-16 units per field)" : L"no") +
+                    L"\r\n\r\nContext and stages:\r\n" + field("context");
+                for (size_t at = 0; (at = row.details.find(L'\n', at)) != row.details.npos; ++at)
+                    if (at == 0 || row.details[at - 1] != L'\r')
+                        row.details.insert(at++, 1, L'\r');
+                rows.push_back(std::move(row));
+                legacy = nullptr;
+                continue;
+            }
+            catch (...)
+            {
+            } // Preserve malformed and old records for diagnosis.
+        }
+        if (line.front() != L' ' || !legacy)
+        {
+            rows.push_back({L"", L"", L"Legacy / event", L"", L"", L"Unstructured event", line});
+            legacy = &rows.back();
+        }
+        else
+            legacy->details += L"\r\n" + line;
+    }
+    return rows;
+}
+inline std::wstring conversionReadbackOutcome(const std::wstring &actual, const std::wstring &original,
+                                              const std::wstring &expected)
+{
+    if (actual == expected)
+        return L"Paste verified";
+    if (actual == original)
+        return L"Original text remained";
+    return L"Readback differs";
+}
+} // namespace ks
@@ -0,0 +1,162 @@
+#pragma once
+#include "platform.h"
+#include <uiautomation.h>
+
+namespace ks
+{
+// Read-only UI Automation: never select, move the caret, or touch the clipboard.
+class PasteProbe
+{
+    IUIAutomation2 *automation{};
+    IUIAutomationElement *element{};
+    IUIAutomationTextPattern *pattern{};
+
+  public:
+    std::wstring status = L"not-requested";
+    PasteProbe(bool enabled, const std::wstring &original)
+    {
+        if (!enabled)
+            return;
+        status = L"accessibility-unavailable";
+        if (FAILED(CoCreateInstance(CLSID_CUIAutomation8, nullptr, CLSCTX_INPROC_SERVER, IID_IUIAutomation2,
+                                    (void **)&automation)))
+            return;
+        automation->put_ConnectionTimeout(200);
+        automation->put_TransactionTimeout(200);
+        if (FAILED(automation->GetFocusedElement(&element)) || !element)
+            return;
+        BOOL password = TRUE;
+        if (FAILED(element->get_CurrentIsPassword(&password)) || password)
+        {
+            status = L"protected-or-inaccessible-field";
+            return;
+        }
+        if (FAILED(element->GetCurrentPatternAs(UIA_TextPatternId, IID_IUIAutomationTextPattern,
+                                                (void **)&pattern)) ||
+            !pattern)
+            return;
+        auto selected = read(1, false);
+        auto normalize = [](std::wstring value)
+        {
+            for (size_t at = 0; (at = value.find(L"\r\n", at)) != value.npos;)
+                value.erase(at, 1);
+            return value;
+        };
+        if (!selected || normalize(*selected) != normalize(original))
+        {
+            if (selected)
+                status = L"initial-selection-mismatch";
+            if (pattern)
+                pattern->Release();
+            pattern = nullptr;
+            return;
+        }
+        status = L"ready";
+    }
+    PasteProbe(const PasteProbe &) = delete;
+    ~PasteProbe()
+    {
+        if (pattern)
+            pattern->Release();
+        if (element)
+            element->Release();
+        if (automation)
+            automation->Release();
+    }
+    std::optional<std::wstring> read(int characters, bool allowCaret = true)
+    {
+        if (!pattern)
+            return {};
+        if (characters <= 0 || characters > 4096)
+        {
+            status = L"readback-size-limit";
+            return {};
+        }
+        IUIAutomationElement *focused{};
+        BOOL same = FALSE;
+        if (SUCCEEDED(automation->GetFocusedElement(&focused)) && focused)
+        {
+            automation->CompareElements(element, focused, &same);
+        }
+        if (!same)
+        {
+            if (focused)
+                focused->Release();
+            status = L"focused-control-changed";
+            return {};
+        }
+        BOOL password = TRUE;
+        if (FAILED(focused->get_CurrentIsPassword(&password)) || password)
+        {
+            focused->Release();
+            status = L"protected-or-inaccessible-field";
+            return {};
+        }
+        // Native Edit accessibility proxies can retain a text snapshot in the
+        // pattern object. Obtain a fresh pattern after paste, not the pre-paste one.
+        pattern->Release();
+        pattern = nullptr;
+        HRESULT refreshed =
+            focused->GetCurrentPatternAs(UIA_TextPatternId, IID_IUIAutomationTextPattern, (void **)&pattern);
+        focused->Release();
+        if (FAILED(refreshed) || !pattern)
+        {
+            status = L"accessibility-unavailable";
+            return {};
+        }
+        IUIAutomationTextRangeArray *ranges{};
+        if (FAILED(pattern->GetSelection(&ranges)) || !ranges)
+        {
+            status = L"selection-unavailable";
+            return {};
+        }
+        int count{};
+        ranges->get_Length(&count);
+        IUIAutomationTextRange *range{};
+        if (count == 1)
+            ranges->GetElement(0, &range);
+        ranges->Release();
+        if (!range)
+        {
+            status = L"selection-ambiguous";
+            return {};
+        }
+        int difference{};
+        HRESULT hr = range->CompareEndpoints(TextPatternRangeEndpoint_Start, range,
+                                             TextPatternRangeEndpoint_End, &difference);
+        if (SUCCEEDED(hr) && difference == 0)
+        {
+            if (!allowCaret)
+            {
+                range->Release();
+                status = L"initial-selection-unavailable";
+                return {};
+            }
+            int moved{};
+            hr = range->MoveEndpointByUnit(TextPatternRangeEndpoint_Start, TextUnit_Character, -characters,
+                                           &moved);
+            if (SUCCEEDED(hr) && moved != -characters)
+                hr = E_FAIL;
+        }
+        BSTR value{};
+        if (SUCCEEDED(hr))
+            hr = range->GetText(8193, &value);
+        range->Release();
+        if (FAILED(hr))
+        {
+            SysFreeString(value);
+            status = L"range-read-failed";
+            return {};
+        }
+        std::wstring text(value ? value : L"", SysStringLen(value));
+        SysFreeString(value);
+        if (text.size() > 8192)
+        {
+            status = L"readback-size-limit";
+            return {};
+        }
+        status = L"read-back-via-accessibility";
+        return text;
+    }
+};
+} // namespace ks
@@ -1,6 +1,8 @@
 #include "platform.h"
+#include "../vendor/json.hpp"
 #include <algorithm>
 #include <fstream>
+#include <iomanip>
 #include <imm.h>
 #include <map>
 #include <mutex>
@@ -624,6 +626,22 @@ void diagnosticEvent(const std::wstring &message, bool problem)
    if (!incident.empty())
        log(incident);
 }
+void diagnosticOperation(const std::string &json)
+{
+    std::lock_guard lock(logGate);
+    if (!loggingEnabled) return;
+    auto record = nlohmann::json::parse(json);
+    if (!record.value("problem", true))
+    {
+        // Keep successful operations only in the bounded, short-lived context.
+        // They are persisted with a subsequent failure, never as standalone rows.
+        diagnosticBuffer.record(L"Completed operation " + wide(record.dump(-1, ' ', true,
+            nlohmann::json::error_handler_t::replace)), false, GetTickCount64());
+        return;
+    }
+    record["context"] = utf8(diagnosticBuffer.record(L"Operation complete", true, GetTickCount64()));
+    log(L"Operation " + wide(record.dump(-1, ' ', true, nlohmann::json::error_handler_t::replace)));
+}
 void log(const std::wstring &message)
 {
    std::lock_guard lock(logGate);
@@ -645,8 +663,9 @@ void log(const std::wstring &message)
        std::ofstream f(path, std::ios::app);
        SYSTEMTIME t;
        GetLocalTime(&t);
-        f << t.wYear << '-' << t.wMonth << '-' << t.wDay << ' ' << t.wHour << ':' << t.wMinute << ':'
-          << t.wSecond << ' ' << utf8(message) << '\n';
+        f << std::setfill('0') << std::setw(4) << t.wYear << '-' << std::setw(2) << t.wMonth << '-'
+          << std::setw(2) << t.wDay << ' ' << std::setw(2) << t.wHour << ':' << std::setw(2) << t.wMinute << ':'
+          << std::setw(2) << t.wSecond << ' ' << utf8(message) << '\n';
    }
    catch (...)
    {
@@ -66,6 +66,7 @@ class DiagnosticBuffer
 };
 void setLoggingEnabled(bool enabled);
 void diagnosticEvent(const std::wstring &message, bool problem = false);
+void diagnosticOperation(const std::string &json);
 std::wstring readDiagnosticLog(bool previous);
 void clearDiagnosticLog(bool previous);
 } // namespace ks
@@ -4,6 +4,7 @@
 #include "ocr.h"
 #include "richtext.h"
 #include "ui_geometry.h"
+#include "diagnostics.h"
 #include <algorithm>
 #include <commctrl.h>
 #include <commdlg.h>
@@ -34,7 +35,7 @@ struct WindowLayout
    bool scrolling{}, arranging{}, history{};
    int wheelRemainder{}, horizontalWheelRemainder{};
    std::vector<std::pair<HWND, RECT>> controls; // Original 96-DPI geometry; never rescale rounded pixels.
-    HWND stretch{}, bottomLeft{}, bottomRight{};
+    HWND stretch{}, bottomLeft{}, bottomRight{}, details{};
    bool autoOptions{};
 };
 WindowLayout *windowLayoutState(HWND w)
@@ -88,6 +89,11 @@ void arrangeWindow(HWND w)
            next.right += extraWidth;
            next.bottom += extraHeight;
        }
+        if (child == layout->details)
+        {
+            next.right += extraWidth;
+            OffsetRect(&next, 0, extraHeight);
+        }
        if (child == layout->bottomLeft || child == layout->bottomRight)
            OffsetRect(&next, child == layout->bottomRight ? extraWidth : 0, extraHeight);
        if (layout->autoOptions)
@@ -311,7 +317,7 @@ std::wstring value(HWND w, int id)
    text.resize(n);
    return text;
 }
-void value(HWND w, int id, const std::wstring &text)
+[[maybe_unused]] void value(HWND w, int id, const std::wstring &text)
 {
    SetDlgItemTextW(w, id, text.c_str());
 }
@@ -1573,248 +1579,7 @@ void showHistory(App &app, bool visible)
 }
 #endif
 #ifndef KS_RESIDENT_APP
-namespace
-{
-constexpr int LogChoice = 601, LogRows = 602, LogRefresh = 603, LogStatus = 604, LogCopy = 605,
-              LogClear = 606;
-void fitLogDetails(HWND list)
-{
-    if (GetPropW(list, L"FittingLogDetails") || Header_GetItemCount(ListView_GetHeader(list)) != 4) return;
-    SetPropW(list, L"FittingLogDetails", (HANDLE)1);
-    RECT client{};
-    GetClientRect(list, &client);
-    int remaining = client.right;
-    for (int column = 0; column < 3; ++column)
-        remaining -= ListView_GetColumnWidth(list, column);
-    int width = std::max(scale(list, 120), remaining);
-    if (ListView_GetColumnWidth(list, 3) != width)
-        ListView_SetColumnWidth(list, 3, width);
-    RemovePropW(list, L"FittingLogDetails");
-}
-LRESULT CALLBACK logListResizeProc(HWND w, UINT msg, WPARAM wp, LPARAM lp, UINT_PTR, DWORD_PTR)
-{
-    auto result = DefSubclassProc(w, msg, wp, lp);
-    if (msg == WM_SIZE)
-        fitLogDetails(w);
-    if (msg == WM_NOTIFY && lp)
-    {
-        auto *header = reinterpret_cast<NMHEADERW *>(lp);
-        if (header->hdr.hwndFrom == ListView_GetHeader(w) &&
-            (header->hdr.code == HDN_ITEMCHANGEDW || header->hdr.code == HDN_ITEMCHANGEDA) &&
-            header->iItem >= 0 && header->iItem < 3)
-            fitLogDetails(w);
-    }
-    if (msg == WM_NCDESTROY) RemoveWindowSubclass(w, logListResizeProc, 3);
-    return result;
-}
-void copyLogRows(HWND w, App &app)
-{
-    HWND list = GetDlgItem(w, LogRows);
-    std::wstring copied;
-    for (int row = ListView_GetNextItem(list, -1, LVNI_SELECTED); row >= 0;
-         row = ListView_GetNextItem(list, row, LVNI_SELECTED))
-    {
-        for (int column = 0; column < 4; ++column)
-        {
-            std::vector<wchar_t> text(32768);
-            ListView_GetItemText(list, row, column, text.data(), (int)text.size());
-            if (column)
-                copied += L'\t';
-            copied += text.data();
-        }
-        copied += L"\r\n";
-    }
-    if (!copied.empty())
-    {
-        auto clip = textClip(copied);
-        clip.formats.push_back({0, L"ExcludeClipboardContentFromMonitorProcessing", {1, 0, 0, 0}});
-        app.ownSequence = writeClipboard(app.window, clip);
-    }
-}
-void refreshLogView(HWND w, App &app)
-{
-    const bool previous = SendDlgItemMessageW(w, LogChoice, CB_GETCURSEL, 0, 0) == 1;
-    std::wstring contents;
-    try
-    {
-        contents = readDiagnosticLog(previous);
-    }
-    catch (const std::exception &e)
-    {
-        contents = L"Could not read the log: " + wide(e.what());
-    }
-    HWND list = GetDlgItem(w, LogRows);
-    SendMessageW(list, WM_SETREDRAW, FALSE, 0);
-    ListView_DeleteAllItems(list);
-    std::wistringstream lines(contents);
-    std::wstring line, timestamp;
-    int row = 0;
-    while (std::getline(lines, line))
-    {
-        if (!line.empty() && line.back() == L'\r')
-            line.pop_back();
-        if (line.empty())
-            continue;
-        auto firstSpace = line.find(L' ');
-        auto secondSpace = firstSpace == line.npos ? line.npos : line.find(L' ', firstSpace + 1);
-        if (iswdigit(line.front()) && line.find(L'-') < firstSpace && secondSpace != line.npos)
-        {
-            timestamp = line.substr(0, secondSpace);
-            line.erase(0, secondSpace + 1);
-        }
-        auto id = line.find(L" id=");
-        std::wstring attempt;
-        if (id != line.npos)
-        {
-            auto end = line.find(L' ', id + 4);
-            attempt = line.substr(id + 4, end == line.npos ? end : end - id - 4);
-        }
-        std::wstring event = line;
-        if (event.starts_with(L"  ageMs="))
-        {
-            auto end = event.find(L' ', 8);
-            if (end != event.npos)
-                event.erase(0, end + 1);
-        }
-        auto equals = event.find(L'=');
-        if (equals != event.npos)
-        {
-            auto key = event.rfind(L' ', equals);
-            if (key != event.npos)
-                event.resize(key);
-        }
-        LVITEMW item{};
-        item.mask = LVIF_TEXT;
-        item.iItem = row;
-        item.pszText = timestamp.data();
-        ListView_InsertItem(list, &item);
-        ListView_SetItemText(list, row, 1, attempt.data());
-        ListView_SetItemText(list, row, 2, event.data());
-        ListView_SetItemText(list, row, 3, line.data());
-        ++row;
-    }
-    SendMessageW(list, WM_SETREDRAW, TRUE, 0);
-    InvalidateRect(list, nullptr, TRUE);
-    if (row)
-        ListView_EnsureVisible(list, row - 1, FALSE);
-    fitLogDetails(list);
-    value(w, LogStatus, app.settings.writeLog ? L"Logging enabled: failed operations only."
-                                    : L"Logging disabled. Showing previously saved entries.");
-}
-LRESULT CALLBACK logProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
-{
-    auto *app = reinterpret_cast<App *>(GetWindowLongPtrW(w, GWLP_USERDATA));
-    if (msg == WM_NCCREATE)
-    {
-        SetWindowLongPtrW(w, GWLP_USERDATA, (LONG_PTR)((CREATESTRUCTW *)lp)->lpCreateParams);
-        return TRUE;
-    }
-    if (!app)
-        return DefWindowProcW(w, msg, wp, lp);
-    switch (msg)
-    {
-    case WM_COMMAND:
-        if ((LOWORD(wp) == LogRefresh && HIWORD(wp) == BN_CLICKED) ||
-            (LOWORD(wp) == LogChoice && HIWORD(wp) == CBN_SELCHANGE))
-        {
-            refreshLogView(w, *app);
-            return 0;
-        }
-        if (LOWORD(wp) == LogCopy && HIWORD(wp) == BN_CLICKED)
-        {
-            try { copyLogRows(w, *app); }
-            catch (const std::exception &e) { error(w, e); }
-            return 0;
-        }
-        if (LOWORD(wp) == LogClear && HIWORD(wp) == BN_CLICKED)
-        {
-            try
-            {
-                app->clearLog(SendDlgItemMessageW(w, LogChoice, CB_GETCURSEL, 0, 0) == 1);
-                refreshLogView(w, *app);
-            }
-            catch (const std::exception &e) { error(w, e); }
-            return 0;
-        }
-        if (LOWORD(wp) != IDCANCEL || HIWORD(wp) != BN_CLICKED)
-            break;
-        [[fallthrough]];
-    case WM_CLOSE:
-        DestroyWindow(w);
-        return 0;
-    case WM_NOTIFY:
-        if (((NMHDR *)lp)->idFrom == LogRows && ((NMHDR *)lp)->code == LVN_KEYDOWN)
-        {
-            auto key = ((NMLVKEYDOWN *)lp)->wVKey;
-            if (GetKeyState(VK_CONTROL) & 0x8000)
-            {
-                if (key == 'A')
-                    ListView_SetItemState(GetDlgItem(w, LogRows), -1, LVIS_SELECTED, LVIS_SELECTED);
-                if (key == 'C')
-                {
-                    try { copyLogRows(w, *app); }
-                    catch (const std::exception &e) { error(w, e); }
-                }
-            }
-        }
-        return 0;
-    case WM_DPICHANGED:
-        resizeForDpi(w, wp, lp);
-        return 0;
-    case WM_NCDESTROY:
-        app->logWindow = nullptr;
-        disposeFont(w);
-        break;
-    }
-    return DefWindowProcW(w, msg, wp, lp);
-}
-}
-void showLogs(App &app)
-{
-    if (app.logWindow)
-    {
-        showRequestedWindow(app.logWindow);
-        activateWindow(app.logWindow);
-        return;
-    }
-    auto w = makeWindow(app, L"KSwitcher.Logs", L"KSwitcher log", logProc, 900, 590);
-    app.logWindow = w;
-    auto choice = control(w, L"COMBOBOX", L"", WS_TABSTOP | CBS_DROPDOWNLIST, LogChoice, 16, 16, 300, 140);
-    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, 330, 14, 110);
-    button(w, L"Copy selected", LogCopy, 454, 14, 140);
-    button(w, L"Clear log", LogClear, 608, 14, 110);
-    control(w, L"STATIC", L"", 0, LogStatus, 16, 52, 860, 22);
-    INITCOMMONCONTROLSEX common{sizeof(common), ICC_LISTVIEW_CLASSES};
-    InitCommonControlsEx(&common);
-    auto list = control(w, WC_LISTVIEWW, L"", WS_TABSTOP | WS_BORDER | LVS_REPORT | LVS_SHOWSELALWAYS,
-                        LogRows, 16, 82, 868, 454);
-    ListView_SetExtendedListViewStyle(list, LVS_EX_FULLROWSELECT | LVS_EX_GRIDLINES | LVS_EX_DOUBLEBUFFER);
-    SetWindowSubclass(list, logListResizeProc, 3, 0);
-    const wchar_t *titles[] = {L"Time", L"Attempt", L"Event", L"Details"};
-    const int widths[] = {155, 65, 195, 900};
-    for (int i = 0; i < 4; ++i)
-    {
-        LVCOLUMNW column{};
-        column.mask = LVCF_TEXT | LVCF_WIDTH;
-        column.pszText = const_cast<wchar_t *>(titles[i]);
-        column.cx = scale(w, widths[i]);
-        ListView_InsertColumn(list, i, &column);
-    }
-    auto hint = control(w, L"STATIC", L"Select rows to copy. Ctrl+A selects all; Ctrl+C copies selected rows.",
-                        0, 0, 16, 551, 720, 22);
-    button(w, L"Close", IDCANCEL, 774, 548, 110);
-    auto *layout = windowLayoutState(w);
-    layout->stretch = list;
-    layout->bottomLeft = hint;
-    layout->bottomRight = GetDlgItem(w, IDCANCEL);
-    arrangeWindow(w);
-    refreshLogView(w, app);
-    showRequestedWindow(w);
-    activateWindow(w);
-}
+#include "ui_log.inl"
 #else
 void showLogs(App &app) { launchConfiguration(app, false, true); }
 #endif
@@ -0,0 +1,357 @@
+// Included inside namespace ks by ui.cpp; shares the native control/layout helpers.
+namespace
+{
+constexpr int LogChoice = 601, LogRows = 602, LogRefresh = 603, LogStatus = 604, LogCopy = 605,
+              LogClear = 606, LogProgram = 607, LogCommand = 608, LogResult = 609, LogProblems = 610,
+              LogDetails = 611, LogReset = 612;
+struct LogViewState
+{
+    std::vector<OperationLogRow> rows;
+    std::vector<size_t> visible;
+    int sortColumn = 0;
+    bool descending = true, rendering = false;
+};
+LogViewState *logState(HWND w)
+{
+    return reinterpret_cast<LogViewState *>(GetPropW(w, L"LogViewState"));
+}
+const std::wstring &logCell(const OperationLogRow &row, int column)
+{
+    switch (column)
+    {
+    case 0:
+        return row.time;
+    case 1:
+        return row.process;
+    case 2:
+        return row.command;
+    case 3:
+        return row.source;
+    case 4:
+        return row.target;
+    default:
+        return row.outcome;
+    }
+}
+void showLogDetails(HWND w)
+{
+    auto *state = logState(w);
+    if (!state || state->rendering)
+        return;
+    int selected = ListView_GetNextItem(GetDlgItem(w, LogRows), -1, LVNI_SELECTED);
+    value(w, LogDetails,
+          selected >= 0 && (size_t)selected < state->visible.size()
+              ? state->rows[state->visible[selected]].details
+              : L"Select an operation to inspect its text and stages.");
+}
+void renderLogRows(HWND w, App &app)
+{
+    auto *state = logState(w);
+    if (!state)
+        return;
+    state->rendering = true;
+    state->visible.clear();
+    auto matches = [&](int id, const std::wstring &field)
+    { return SendDlgItemMessageW(w, id, CB_GETCURSEL, 0, 0) <= 0 || value(w, id) == field; };
+    for (size_t i = 0; i < state->rows.size(); ++i)
+    {
+        const auto &row = state->rows[i];
+        if (matches(LogProgram, row.process) && matches(LogCommand, row.command) &&
+            matches(LogResult, row.outcome) && (!checked(w, LogProblems) || row.problem))
+            state->visible.push_back(i);
+    }
+    std::stable_sort(state->visible.begin(), state->visible.end(),
+                     [&](size_t a, size_t b)
+                     {
+                         const auto &left = logCell(state->rows[a], state->sortColumn);
+                         const auto &right = logCell(state->rows[b], state->sortColumn);
+                         if (left == right)
+                             return state->descending ? a > b : a < b;
+                         int comparison = CompareStringOrdinal(left.c_str(), -1, right.c_str(), -1, TRUE);
+                         return state->descending ? comparison == CSTR_GREATER_THAN
+                                                  : comparison == CSTR_LESS_THAN;
+                     });
+    HWND list = GetDlgItem(w, LogRows);
+    SendMessageW(list, WM_SETREDRAW, FALSE, 0);
+    ListView_DeleteAllItems(list);
+    for (size_t i = 0; i < state->visible.size(); ++i)
+    {
+        const auto &row = state->rows[state->visible[i]];
+        LVITEMW item{};
+        item.mask = LVIF_TEXT;
+        item.iItem = (int)i;
+        item.pszText = const_cast<wchar_t *>(row.time.c_str());
+        ListView_InsertItem(list, &item);
+        for (int column = 1; column < 6; ++column)
+            ListView_SetItemText(list, (int)i, column, const_cast<wchar_t *>(logCell(row, column).c_str()));
+    }
+    HWND header = ListView_GetHeader(list);
+    for (int i = 0; i < 6; ++i)
+    {
+        HDITEMW item{};
+        item.mask = HDI_FORMAT;
+        Header_GetItem(header, i, &item);
+        item.fmt &= ~(HDF_SORTUP | HDF_SORTDOWN);
+        if (i == state->sortColumn)
+            item.fmt |= state->descending ? HDF_SORTDOWN : HDF_SORTUP;
+        Header_SetItem(header, i, &item);
+    }
+    SendMessageW(list, WM_SETREDRAW, TRUE, 0);
+    InvalidateRect(list, nullptr, TRUE);
+    state->rendering = false;
+    value(w, LogStatus,
+          std::to_wstring(state->visible.size()) + L" of " + std::to_wstring(state->rows.size()) +
+              L" operations / events. " +
+              (app.settings.writeLog ? L"Diagnostic logging enabled."
+                                     : L"Logging disabled; saved entries only."));
+    if (!state->visible.empty())
+        ListView_SetItemState(list, 0, LVIS_SELECTED | LVIS_FOCUSED, LVIS_SELECTED | LVIS_FOCUSED);
+    showLogDetails(w);
+    if (state->visible.empty())
+        value(w, LogDetails,
+              state->rows.empty()
+                  ? L"No recorded operations. Use a conversion shortcut with logging enabled, then refresh."
+                  : L"No operations match these filters. Reset filters to show all entries.");
+}
+void fillLogFilter(HWND w, int id, const std::set<std::wstring> &choices)
+{
+    auto previous = value(w, id);
+    HWND combo = GetDlgItem(w, id);
+    SendMessageW(combo, CB_RESETCONTENT, 0, 0);
+    SendMessageW(combo, CB_ADDSTRING, 0, (LPARAM)L"All");
+    int selected = 0, index = 1;
+    for (const auto &choice : choices)
+    {
+        if (choice.empty())
+            continue;
+        SendMessageW(combo, CB_ADDSTRING, 0, (LPARAM)choice.c_str());
+        if (choice == previous)
+            selected = index;
+        ++index;
+    }
+    SendMessageW(combo, CB_SETCURSEL, selected, 0);
+}
+void refreshLogView(HWND w, App &app)
+{
+    auto *state = logState(w);
+    if (!state)
+        return;
+    try
+    {
+        auto contents = readDiagnosticLog(SendDlgItemMessageW(w, LogChoice, CB_GETCURSEL, 0, 0) == 1);
+        state->rows = parseOperationLog(contents);
+        if (contents.starts_with(L"No log yet.") || contents.starts_with(L"No previous log") ||
+            contents == L"The log is empty.")
+            state->rows.clear();
+        std::set<std::wstring> programs, commands, results;
+        for (const auto &row : state->rows)
+        {
+            programs.insert(row.process);
+            commands.insert(row.command);
+            results.insert(row.outcome);
+        }
+        fillLogFilter(w, LogProgram, programs);
+        fillLogFilter(w, LogCommand, commands);
+        fillLogFilter(w, LogResult, results);
+        renderLogRows(w, app);
+    }
+    catch (const std::exception &e)
+    {
+        value(w, LogStatus, L"Could not read the log: " + wide(e.what()));
+    }
+}
+void copyLogRows(HWND w, App &app)
+{
+    auto *state = logState(w);
+    if (!state)
+        return;
+    std::wstring copied;
+    HWND list = GetDlgItem(w, LogRows);
+    for (int row = ListView_GetNextItem(list, -1, LVNI_SELECTED); row >= 0;
+         row = ListView_GetNextItem(list, row, LVNI_SELECTED))
+    {
+        if ((size_t)row >= state->visible.size())
+            continue;
+        const auto &entry = state->rows[state->visible[row]];
+        copied += entry.time + L"\t" + entry.process + L"\t" + entry.command + L"\t" + entry.source +
+                  L" -> " + entry.target + L"\t" + entry.outcome + L"\r\n" + entry.details + L"\r\n\r\n";
+    }
+    if (!copied.empty())
+    {
+        auto clip = textClip(copied);
+        clip.formats.push_back({0, L"ExcludeClipboardContentFromMonitorProcessing", {1, 0, 0, 0}});
+        app.ownSequence = writeClipboard(app.window, clip);
+    }
+}
+LRESULT CALLBACK logProc(HWND w, UINT msg, WPARAM wp, LPARAM lp)
+{
+    auto *app = reinterpret_cast<App *>(GetWindowLongPtrW(w, GWLP_USERDATA));
+    if (msg == WM_NCCREATE)
+    {
+        SetWindowLongPtrW(w, GWLP_USERDATA, (LONG_PTR)((CREATESTRUCTW *)lp)->lpCreateParams);
+        SetPropW(w, L"LogViewState", new LogViewState);
+        return TRUE;
+    }
+    if (!app)
+        return DefWindowProcW(w, msg, wp, lp);
+    switch (msg)
+    {
+    case WM_COMMAND:
+        if ((LOWORD(wp) == LogRefresh && HIWORD(wp) == BN_CLICKED) ||
+            (LOWORD(wp) == LogChoice && HIWORD(wp) == CBN_SELCHANGE))
+        {
+            refreshLogView(w, *app);
+            return 0;
+        }
+        if ((LOWORD(wp) >= LogProgram && LOWORD(wp) <= LogResult && HIWORD(wp) == CBN_SELCHANGE) ||
+            (LOWORD(wp) == LogProblems && HIWORD(wp) == BN_CLICKED))
+        {
+            renderLogRows(w, *app);
+            return 0;
+        }
+        if (LOWORD(wp) == LogReset && HIWORD(wp) == BN_CLICKED)
+        {
+            for (int id : {LogProgram, LogCommand, LogResult})
+                SendDlgItemMessageW(w, id, CB_SETCURSEL, 0, 0);
+            CheckDlgButton(w, LogProblems, BST_UNCHECKED);
+            renderLogRows(w, *app);
+            return 0;
+        }
+        if (LOWORD(wp) == LogCopy && HIWORD(wp) == BN_CLICKED)
+        {
+            try
+            {
+                copyLogRows(w, *app);
+            }
+            catch (const std::exception &e)
+            {
+                error(w, e);
+            }
+            return 0;
+        }
+        if (LOWORD(wp) == LogClear && HIWORD(wp) == BN_CLICKED)
+        {
+            try
+            {
+                app->clearLog(SendDlgItemMessageW(w, LogChoice, CB_GETCURSEL, 0, 0) == 1);
+                refreshLogView(w, *app);
+            }
+            catch (const std::exception &e)
+            {
+                error(w, e);
+            }
+            return 0;
+        }
+        if (LOWORD(wp) != IDCANCEL || HIWORD(wp) != BN_CLICKED)
+            break;
+        [[fallthrough]];
+    case WM_CLOSE:
+        DestroyWindow(w);
+        return 0;
+    case WM_NOTIFY:
+        if (((NMHDR *)lp)->idFrom != LogRows)
+            break;
+        if (((NMHDR *)lp)->code == LVN_ITEMCHANGED)
+            showLogDetails(w);
+        if (((NMHDR *)lp)->code == LVN_COLUMNCLICK)
+        {
+            auto *state = logState(w);
+            int column = ((NMLISTVIEW *)lp)->iSubItem;
+            state->descending = state->sortColumn == column ? !state->descending : false;
+            state->sortColumn = column;
+            renderLogRows(w, *app);
+        }
+        if (((NMHDR *)lp)->code == LVN_KEYDOWN)
+        {
+            auto key = ((NMLVKEYDOWN *)lp)->wVKey;
+            if (GetKeyState(VK_CONTROL) & 0x8000)
+            {
+                if (key == 'A')
+                    ListView_SetItemState(GetDlgItem(w, LogRows), -1, LVIS_SELECTED, LVIS_SELECTED);
+                if (key == 'C')
+                {
+                    try
+                    {
+                        copyLogRows(w, *app);
+                    }
+                    catch (const std::exception &e)
+                    {
+                        error(w, e);
+                    }
+                }
+            }
+        }
+        return 0;
+    case WM_DPICHANGED:
+        resizeForDpi(w, wp, lp);
+        return 0;
+    case WM_NCDESTROY:
+        delete logState(w);
+        RemovePropW(w, L"LogViewState");
+        app->logWindow = nullptr;
+        disposeFont(w);
+        break;
+    }
+    return DefWindowProcW(w, msg, wp, lp);
+}
+} // namespace
+void showLogs(App &app)
+{
+    if (app.logWindow)
+    {
+        showRequestedWindow(app.logWindow);
+        activateWindow(app.logWindow);
+        return;
+    }
+    auto w = makeWindow(app, L"KSwitcher.Logs", L"KSwitcher diagnostic operations", logProc, 1100, 760);
+    app.logWindow = w;
+    auto choice = control(w, L"COMBOBOX", L"", WS_TABSTOP | CBS_DROPDOWNLIST, LogChoice, 16, 16, 280, 140);
+    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);
+    control(w, L"STATIC", L"", 0, LogStatus, 16, 49, 1068, 22);
+    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);
+    control(w, L"COMBOBOX", L"", WS_TABSTOP | CBS_DROPDOWNLIST | WS_VSCROLL, LogCommand, 206, 101, 204, 300);
+    label(w, L"Result", 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);
+    INITCOMMONCONTROLSEX common{sizeof(common), ICC_LISTVIEW_CLASSES};
+    InitCommonControlsEx(&common);
+    auto list = control(w, WC_LISTVIEWW, L"", WS_TABSTOP | WS_BORDER | LVS_REPORT | LVS_SHOWSELALWAYS,
+                        LogRows, 16, 142, 1068, 260);
+    ListView_SetExtendedListViewStyle(list, LVS_EX_FULLROWSELECT | LVS_EX_GRIDLINES | LVS_EX_DOUBLEBUFFER |
+                                                LVS_EX_INFOTIP);
+    const wchar_t *titles[] = {L"Time",          L"Program",       L"Command",
+                               L"Source layout", L"Target layout", L"Result"};
+    const int widths[] = {165, 145, 150, 130, 130, 320};
+    for (int i = 0; i < 6; ++i)
+    {
+        LVCOLUMNW column{};
+        column.mask = LVCF_TEXT | LVCF_WIDTH;
+        column.pszText = const_cast<wchar_t *>(titles[i]);
+        column.cx = scale(w, widths[i]);
+        ListView_InsertColumn(list, i, &column);
+    }
+    auto details = edit(w, LogDetails, 16, 416, 1068, 276,
+                        ES_MULTILINE | ES_AUTOVSCROLL | ES_READONLY | WS_VSCROLL | WS_BORDER);
+    auto hint = control(
+        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);
+    auto *layout = windowLayoutState(w);
+    layout->stretch = list;
+    layout->details = details;
+    layout->bottomLeft = hint;
+    layout->bottomRight = GetDlgItem(w, IDCANCEL);
+    arrangeWindow(w);
+    refreshLogView(w, app);
+    showRequestedWindow(w);
+    activateWindow(w);
+}
@@ -2,7 +2,7 @@
 #include "platform.h"
 namespace ks
 {
-inline constexpr wchar_t AppVersion[] = L"0.6.17";
+inline constexpr wchar_t AppVersion[] = L"0.6.18";
 inline constexpr UINT UpdateMessage = WM_APP + 7;
 inline constexpr UINT UpdateCheckIntervalMs = 6 * 60 * 60 * 1000;
 inline constexpr UINT UpdateNotificationRetryMs = 5 * 60 * 1000;
@@ -39,7 +39,7 @@ $checks=0
 function Assert($ok,$label) { if (!$ok) { throw $label }; $script:checks++ }
 function Window($class) {
    for($i=0;$i -lt 100;$i++) {
-        $title=switch($class){'KSwitcher.Main'{'KSwitcher'};'KSwitcher.Settings'{'KSwitcher settings'};'KSwitcher.Snippets'{'Text snippets'};'KSwitcher.Logs'{'KSwitcher log'}}
+        $title=switch($class){'KSwitcher.Main'{'KSwitcher'};'KSwitcher.Settings'{'KSwitcher settings'};'KSwitcher.Snippets'{'Text snippets'};'KSwitcher.Logs'{'KSwitcher diagnostic operations'}}
        $window=[ConfigurationTestUi]::FindWindow($class,$title)
        if($window -ne [IntPtr]::Zero){return $window}
        Start-Sleep -Milliseconds 50
@@ -1,4 +1,5 @@
 #include "app.h"
+#include "diagnostics.h"
 #include <algorithm>
 #include <iostream>
 #include <fstream>
@@ -21,9 +22,16 @@ ks::App *app{};
 HWND host{}, field{};
 ks::Clip saved;
 bool captured = false, failed = false;
+bool conversionOnly = false;
+int pasteBehavior = 0;
 int enterPresses = 0;
 LRESULT CALLBACK observeEnter(HWND w, UINT message, WPARAM wp, LPARAM lp, UINT_PTR, DWORD_PTR)
 {
+    if (message == WM_PASTE && pasteBehavior)
+    {
+        if (pasteBehavior == 2) SendMessageW(w, EM_REPLACESEL, TRUE, (LPARAM)L"other!");
+        return 0;
+    }
    if (message == WM_KEYDOWN && wp == VK_RETURN) ++enterPresses;
    return DefSubclassProc(w, message, wp, lp);
 }
@@ -178,12 +186,20 @@ LRESULT CALLBACK procedure(HWND w, UINT msg, WPARAM wp, LPARAM lp)
                            "busy conversion attempt is logged");
                    require(diagnostics.find("repeat=3") != std::string::npos,
                            "three repeated conversion attempts are logged");
-                    require(diagnostics.find("reason=recent-verification-mismatch") != std::string::npos,
+                    require(diagnostics.find("\"outcome\":\"recent-verification-mismatch\"") != std::string::npos,
                            "failed recent-word verification has explicit outcome");
-                    require(diagnostics.find("copied=\"abcdef\"") != std::string::npos &&
-                                diagnostics.find("physicalKeys=\"ghbdtn\"") != std::string::npos,
+                    require(diagnostics.find("\"original\":\"abcdef\"") != std::string::npos &&
+                                diagnostics.find("physicalKeys=\\\"ghbdtn\\\"") != std::string::npos,
                            "conversion diagnostics contain actual text and physical input for reproduction");
                }
+                if (conversionOnly)
+                {
+                    pasteBehavior = 1;
+                    prepare(L"ghbdtn", true);
+                    app->transform(ks::Direct + ru);
+                    stage = 40;
+                    break;
+                }
                app->settings.snippets = {{L";addr", L"LINE1\r\n{cursor}LINE2"}};
                prepare(L"prefix ;addr", false);
                record(L";addr");
@@ -289,6 +305,45 @@ LRESULT CALLBACK procedure(HWND w, UINT msg, WPARAM wp, LPARAM lp)
                require(text() == punctuationCases.back().first, "undo preserves custom punctuation");
                stage = 20;
                break;
+            case 40:
+            {
+                auto rows = ks::parseOperationLog(ks::wide(diagnosticLog()));
+                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");
+                pasteBehavior = 2;
+                prepare(L"ghbdtn", true);
+                app->transform(ks::Direct + ru);
+                break;
+            }
+            case 41:
+            {
+                auto rows = ks::parseOperationLog(ks::wide(diagnosticLog()));
+                require(text() == L"other!" && rows.back().outcome == L"Readback differs",
+                        "unexpected editor content records readback mismatch");
+                pasteBehavior = 0;
+                prepare(L"привет", true);
+                app->transform(ks::Direct + ru);
+                break;
+            }
+            case 42:
+            {
+                auto rows = ks::parseOperationLog(ks::wide(diagnosticLog()));
+                require(text() == L"привет" && rows.back().outcome == L"Conversion unchanged" && rows.back().problem,
+                        "manual unchanged conversion is recorded as a problem");
+                diagnosticStart = diagnosticLog().size();
+                app->settings.writeLog = false;
+                ks::setLoggingEnabled(false);
+                prepare(L"ghbdtn", true);
+                app->transform(ks::Direct + ru);
+                break;
+            }
+            case 43:
+                require(text() == L"привет" && diagnosticLog().size() == diagnosticStart,
+                        "disabled diagnostics preserves conversion and writes no records");
+                ks::setLoggingEnabled(true);
+                finish();
+                break;
            case 30:
            case 32:
            case 34:
@@ -448,6 +503,7 @@ LRESULT CALLBACK procedure(HWND w, UINT msg, WPARAM wp, LPARAM lp)
 } // namespace
 int main(int argc, char **argv)
 {
+    conversionOnly = argc > 1 && std::string(argv[1]) == "--conversion-only";
    CoInitializeEx(nullptr, COINIT_APARTMENTTHREADED);
    auto root = std::filesystem::temp_directory_path() /
                (L"KSwitcher-integration-" + std::to_wstring(GetCurrentProcessId()));
@@ -463,9 +519,22 @@ int main(int argc, char **argv)
                ks::showLogs(instance);
                HWND viewer = instance.logWindow;
                HWND rows = GetDlgItem(viewer, 602);
+                if (argc > 2 && std::string(argv[2]) == "--preview")
+                {
+                    MSG message{};
+                    while (IsWindow(viewer) && GetMessageW(&message, nullptr, 0, 0) > 0)
+                    {
+                        TranslateMessage(&message); DispatchMessageW(&message);
+                    }
+                    CoUninitialize();
+                    return 0;
+                }
                require(rows && (GetWindowLongPtrW(rows, GWL_STYLE) & LVS_TYPEMASK) == LVS_REPORT,
                        "log viewer uses report ListView");
-                require(Header_GetItemCount(ListView_GetHeader(rows)) == 4, "log viewer has four columns");
+                require(Header_GetItemCount(ListView_GetHeader(rows)) == 6, "log viewer has six sortable columns");
+                require(GetDlgItem(viewer, 607) && GetDlgItem(viewer, 608) && GetDlgItem(viewer, 609) &&
+                            GetDlgItem(viewer, 610) && GetDlgItem(viewer, 611),
+                        "log viewer exposes program, command, result, problems filter and detail panel");
                require(GetDlgItem(viewer, IDCANCEL) != rows, "log rows and Close have different IDs");
                SetFocus(rows);
                SendMessageW(viewer, WM_COMMAND, MAKEWPARAM(IDCANCEL, EN_SETFOCUS), (LPARAM)rows);
@@ -475,10 +544,11 @@ int main(int argc, char **argv)
                ks::showLogs(instance);
                require(instance.logWindow == viewer, "opening logs reuses the existing window");
                SendMessageW(viewer, WM_COMMAND, MAKEWPARAM(603, BN_CLICKED), (LPARAM)GetDlgItem(viewer, 603));
-                require(IsWindow(viewer) && ListView_GetItemCount(rows) > 0, "refresh populates log rows");
+                require(IsWindow(viewer), "refresh keeps log viewer open");
                SendDlgItemMessageW(viewer, 601, CB_SETCURSEL, 1, 0);
                SendMessageW(viewer, WM_COMMAND, MAKEWPARAM(601, CBN_SELCHANGE), (LPARAM)GetDlgItem(viewer, 601));
-                require(IsWindow(viewer) && ListView_GetItemCount(rows) > 0, "previous log or empty state is displayed");
+                require(IsWindow(viewer) && GetWindowTextLengthW(GetDlgItem(viewer, 611)) > 0,
+                        "previous log or explicit empty state is displayed");
                if (argc > 2 && std::string(argv[2]) == "--clear-test")
                {
                    require(std::filesystem::path(ks::executable()).parent_path().filename() == L"log-clear-test",
@@ -503,7 +573,46 @@ int main(int argc, char **argv)
                    require(newLog.find(L"new-problem") != std::wstring::npos &&
                                newLog.find(L"buffered-before-clear") == std::wstring::npos,
                            "logging resumes after clear without stale context");
+                    ks::DiagnosticJson operation{{"attempt", "1"}, {"process", "alpha.exe"},
+                        {"command", "Convert / cycle"}, {"source", "English"}, {"target", "Ukrainian"},
+                        {"outcome", "Paste verified"}, {"problem", false}, {"original", "ghbdsn"},
+                        {"expected", ks::utf8(L"привіт")}, {"actual", ks::utf8(L"привіт")}};
+                    ks::clearDiagnosticLog(false);
+                    const auto successfulOperation = operation;
+                    for (int attempt = 0; attempt < 1000; ++attempt)
+                        ks::diagnosticOperation(operation.dump());
+                    require(!std::filesystem::exists(logRoot / L"kswitcher.log"),
+                            "one thousand successful operations create no log file");
+                    operation["attempt"] = "2"; operation["process"] = "beta.exe";
+                    operation["outcome"] = "Original text remained"; operation["problem"] = true;
+                    operation["actual"] = operation["original"];
+                    ks::diagnosticOperation(operation.dump());
+                    auto problems = ks::parseOperationLog(ks::readDiagnosticLog(false));
+                    require(problems.size() == 1 && problems[0].process == L"beta.exe" &&
+                                problems[0].details.find(L"Completed operation") != std::wstring::npos &&
+                                problems[0].details.find(L"Paste verified") != std::wstring::npos,
+                            "failure writes one row with bounded preceding successful context");
+                    // Pre-existing successful records remain viewable and filterable.
+                    ks::log(L"Operation " + ks::wide(successfulOperation.dump()));
+                    SendMessageW(viewer, WM_COMMAND, MAKEWPARAM(603, BN_CLICKED), 0);
+                    require(ListView_GetItemCount(rows) == 2, "one visible row per recorded operation");
+                    CheckDlgButton(viewer, 610, BST_CHECKED);
+                    SendMessageW(viewer, WM_COMMAND, MAKEWPARAM(610, BN_CLICKED), 0);
+                    require(ListView_GetItemCount(rows) == 1, "only problems hides verified operations");
+                    SendDlgItemMessageW(viewer, 607, CB_SETCURSEL, 1, 0);
+                    SendMessageW(viewer, WM_COMMAND, MAKEWPARAM(607, CBN_SELCHANGE), 0);
+                    require(ListView_GetItemCount(rows) == 0, "program filter combines with problems filter");
+                    SendMessageW(viewer, WM_COMMAND, MAKEWPARAM(612, BN_CLICKED), 0);
+                    require(ListView_GetItemCount(rows) == 2, "reset restores all operation rows");
+                    NMLISTVIEW sort{}; sort.hdr = {rows, 602, LVN_COLUMNCLICK}; sort.iSubItem = 1;
+                    SendMessageW(viewer, WM_NOTIFY, 602, (LPARAM)&sort);
+                    wchar_t firstProgram[64]{};
+                    ListView_GetItemText(rows, 0, 1, firstProgram, 64);
+                    require(std::wstring(firstProgram) == L"alpha.exe", "clicking program column sorts rows");
+                    require(GetWindowTextLengthW(GetDlgItem(viewer, 611)) > 0, "selected operation populates detail panel");
                }
+                SendDlgItemMessageW(viewer, 601, CB_SETCURSEL, 0, 0);
+                SendMessageW(viewer, WM_COMMAND, MAKEWPARAM(603, BN_CLICKED), 0);
                auto savedClipboard = ks::readClipboard(viewer);
                instance.window = viewer;
                try
@@ -2,6 +2,7 @@
 #include "ocr.h"
 #include "richtext.h"
 #include "storage.h"
+#include "diagnostics.h"
 #include <algorithm>
 #include <iostream>
 #include <map>
@@ -44,6 +45,34 @@ int main(int argc, char **argv)
    }
    try
    {
+        {
+            ks::DiagnosticJson record{{"attempt", "42"}, {"process", "editor.exe"}, {"command", "Convert / cycle"},
+                {"source", "English"}, {"target", "Ukrainian"}, {"outcome", "Original text remained"},
+                {"problem", true}, {"verification", "read-back-via-accessibility"},
+                {"original", "hello\n\"quoted\""}, {"expected", ks::utf8(L"привіт")}, {"actual", "hello"},
+                {"context", "copy\npaste"}};
+            auto encoded = L"2026-10-31 12:00:00 Operation " + ks::wide(record.dump());
+            auto rows = ks::parseOperationLog(encoded);
+            require(rows.size() == 1 && rows[0].process == L"editor.exe" && rows[0].problem,
+                    "structured operation is one filterable row");
+            require(rows[0].details.find(L"привіт") != std::wstring::npos &&
+                    rows[0].details.find(L"copy\r\npaste") != std::wstring::npos,
+                    "operation details preserve Unicode and normalize multiline text");
+            record["problem"] = false;
+            record["outcome"] = "Paste verified";
+            rows = ks::parseOperationLog(encoded + L"\n2026-10-31 12:00:01 Operation " + ks::wide(record.dump()));
+            require(rows.size() == 2 && !rows[1].problem, "verified operations remain distinguishable from problems");
+            rows = ks::parseOperationLog(L"old incident\n  first stage\n  second stage\n2026-10-31 Operation {broken");
+            require(rows.size() == 2 && rows[0].details.find(L"second stage") != std::wstring::npos &&
+                    rows[1].details.find(L"{broken") != std::wstring::npos,
+                    "legacy context is grouped and malformed records remain inspectable");
+            require(ks::conversionReadbackOutcome(L"new", L"old", L"new") == L"Paste verified",
+                    "expected readback verifies paste");
+            require(ks::conversionReadbackOutcome(L"old", L"old", L"new") == L"Original text remained",
+                    "original readback identifies unchanged editor text");
+            require(ks::conversionReadbackOutcome(L"other", L"old", L"new") == L"Readback differs",
+                    "unexpected readback is never reported as success");
+        }
        require(ks::diagnosticText(L"word") == L"\"word\" units=4 truncated=0",
                "diagnostic word preserved");
        require(ks::diagnosticText(L"\"\\\n\r\t") ==