Sync with testing.

docs/testing/qt-control-states.md

@@ -55,6 +55,52 @@ go test ./internal/atspi ./internal/presentation ./internal/app -count=1
 CTHULHU_NATIVE_BROWSER_TESTS=menu /usr/bin/python3 tests/native_browser.py
 ```
 
+## Editable combos with read-only editors
+
+Some Qt applications make a combo editable, then make its internal line edit
+read-only. Qt can expose that child with both EDITABLE and READ_ONLY states.
+Closed Up/Down navigation sends child caret events followed by a name/value
+event from the combo. A caret event can arrive without a new focus event.
+
+On Slint with Qt/PySide6 6.9.3 and AT-SPI 2.58.1, querying the word at that
+child's caret reproduced an 800 ms timeout, followed by stale list-item
+queries and loss of further accessibility events. Cthulhu identifies these
+children using READ_ONLY plus a direct combo parent, copies that parent's
+identity into each caret snapshot, and omits the unused word query. It keeps
+native focus on the combo and lets its name/value event present the selection.
+This does not depend on the last caret/focus event or on a coalescing delay.
+Writable combo editors and standalone read-only text fields retain word capture.
+
+The app event loop suppresses a child caret only when its copied combo identity
+matches the owned focus. Normal foreground checks still apply. Popup selection
+followed by focus is presented once, and deselection of the previous managed
+item does not replace the current item. Deselection of the current focused
+item remains audible.
+
+Run the isolated regression with:
+
+```sh
+python3 tests/native_toby_combo.py
+```
+
+This requires PySide6, Xvfb, xdotool and the native Go build dependencies. It
+explicitly uses a 24-bit screen; Slint's 8-bit Xvfb default can crash Qt's text
+cursor painter before accessibility checks complete. Fixture diagnostics are
+saved in the printed `/tmp/cthulhu-combo-qt-*.log` path. The test
+checks consecutive closed arrows, Home/End, popup Return and Escape,
+Tab/Shift+Tab after each close, and word capture in writable fields, standalone
+read-only fields and writable combo editors. It waits for each provider event
+instead of filling the adapter queue with an unobserved key sequence. Snapshot
+timings are reported for diagnosis, without a machine-speed pass threshold.
+
+For live acceptance, repeat those keys in Toby Doom Launcher for both IWAD and
+game choices. Confirm each new value is spoken once, navigation continues after
+several changes, and Tab/Shift+Tab still reaches narration and buttons. In an
+ordinary text field and writable combo, check typing and Ctrl+Left/Right word
+reading. Switch away with a popup open and confirm background events do not
+interrupt the new foreground application. Check a physical Braille display when
+available; private event tests do not establish audible or physical output.
+
 ## Providers which omit checkability
 
 The tested Mumble 1.5.939 / Qt 5 installation exports Mute Self and Deafen Self