- Process arrow keys BEFORE input_text so the input field does not consume them
- Up/Down arrow keys navigate the result list (clamped to bounds)
- Enter and KeypadEnter execute the currently selected command
- Refactored _close_palette and _execute helpers (action call is now wrapped in try/except via _execute)
- Added 3 new tests: close helper resets state, execute runs and catches exceptions, top_n is meaningful for navigation