* feat(tui): implement completion popup rendering and windowing logic
* feat(tui): enhance completion popup with dynamic row budgeting and CSS adjustments
* Refactor picker widgets to use shared base class for improved code reuse
- Introduced `picker_base.py` to encapsulate common functionality for picker widgets.
- Updated `ModelPickerWidget`, `SkillBrowserWidget`, and `ThreadPickerWidget` to inherit from `PickerWidgetBase`.
- Implemented selection helpers (`first_selectable_index`, `move_selection`) in `picker_base.py` for consistent item navigation.
- Refactored rendering and selection logic in each widget to utilize the new base class methods.
- Added tests for picker functionality to ensure behavior remains consistent post-refactor.
* feat: Enhance ModelPickerWidget for Ollama integration
- Implemented a sentinel row for "Custom Ollama model..." in ModelPickerWidget, allowing users to input arbitrary model names.
- Updated action handling in ModelPickerWidget to manage transitions between list and input modes.
- Added async model discovery for Ollama models, integrating with the /model command to fetch locally installed models.
- Created tests for Ollama model discovery and ModelPickerWidget behavior, ensuring proper functionality and user experience.
- Refactored validate_ollama_connection and discover_ollama_models for improved error handling and response management.
* fix: Simplify code by removing unnecessary line breaks in ModelPickerWidget and test cases
* fix: Restore globals on set_chat_model failure to prevent half-switched session
* fix: Improve error handling in ModelCommand by restoring globals on failure
Xi Zhang