e8399b7c94
* 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.