Release v0.6.36: offload notification registration and mitigate Viber paste timing

tests/screenshot_registration.cpp

@@ -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();