edac618351
The HTML session export bound "toggle thinking" and "toggle tools" to `Ctrl+T` and `Ctrl+O`. Both are reserved by every major browser (new tab and open file), so the chord never reached the page and the advertised toggles were unreachable. Switch to bare `T` / `O`, ignore the keystroke while focus is in an `<input>`/`<textarea>`/`[contenteditable]` (so the sidebar search still accepts those letters), and let any chord with Ctrl/Meta/Alt pass through to the browser. Help bar updated to match. Fixes #3670