Improve soundpack manager UX and fix accessibility issues

- Fix confusing "Available Soundpacks" tab that only showed repository downloads
- Now shows ALL usable soundpacks: bundled, installed, and downloadable
- Add clear status indicators: (Bundled), (Built-in), (Installed), (Available for download)
- Enable keyboard text navigation in soundpack description boxes
- Add comprehensive debug logging for troubleshooting soundpack discovery
- Update CLAUDE.md with critical note about print() statements in Qt apps

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

CLAUDE.md

@@ -10,6 +10,7 @@
 ## Logging System
 - Bifrost uses a centralized logging system configured in `bifrost.py`
 - **NEVER use print() statements for debugging** - always use the logging system
+- **CRITICAL: print() statements get buried in Qt terminal spam and are useless for debugging**
 - To enable debug logging, run bifrost with the `-d` flag:
   - `DISPLAY=:0 python bifrost.py -d` for console debug output
   - `DISPLAY=:0 python bifrost.py -d bifrost.log` for debug to file