- Add internal state tracking (_active_category, _active_manufacturer) to Sidebar
- Cmd+3/4 now restores previously selected category/manufacturer instead of always selecting first
- Manufacturer gray highlight remains when clicking a plugin (filter still active)
- Pressing Enter on plugin or sidebar now highlights plugin's categories
- All focus/selection uses proper selectionModel.setCurrentIndex with ClearAndSelect flag
Replace alphabetical sorting with user-defined order from logic-plugin-manager.
Categories now display according to their index property, preserving both
top-level and nested category ordering as specified in Logic Pro.
