## Critical Blockers Fixed
- Remove playbackState.addError() which broke audio_service permanently
- Move error handling from audio_handler to song_list where UI context exists
- Display error in SnackBar instead of destroying playback stream
- Add escapeChar parameter to LIKE queries for correct wildcard handling
- Fixes broken search for titles with _ or % characters
- Add dismissScanError() method to allow closing error banner
- Previously banner couldn't be dismissed (missing notifyListeners())
## Improvements
- Remove dead livePaths list, use companions.isNotEmpty instead
- Add initial progress update to show total files when scan starts
- Add tooltip to now_playing_screen Zurück button
- Add proper error handling in song_list with async/await
## Testing
- Add regression test for CRITICAL-1: empty scan doesn't delete songs
- Add regression test for CRITICAL-2: tombstoned files restore on re-scan
- All 11 tests pass
Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>
