## 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>
## Critical Fixes
- Fix CRITICAL-1: Empty scans no longer delete entire library
- Use timestamp-based tombstone logic instead of path-based
- Only mark missing if livePaths is not empty
- Fix CRITICAL-2: Re-scanned files now return from deleted state
- Add deleted=false to SongsCompanion.insert in both scanners
## High Priority Fixes
- HIGH-1: Fix SQLite variable limit crash on large libraries
- Replace isNotIn() with timestamp comparison (O(1) not O(n))
- HIGH-2: Fix UI freezing during scan
- Throttle progress updates (every 50 files or end of scan)
- HIGH-3: Add error handling for scan failures
- Wrap scanFolders/scanAndroidMediaStore in try/catch
- Display scanError banner in LibraryScreen
- HIGH-4: Add error handling for playback failures
- Wrap loadPlaylist in try/catch
## Medium Priority Fixes
- MEDIUM-1: Replace ! with ?? to handle unknown ProcessingState
- MEDIUM-2: Escape LIKE wildcards in search queries
- MEDIUM-4: Display StreamBuilder errors instead of treating as empty
- MEDIUM-8: Add tooltips to all IconButtons for accessibility
- Add doc comments to public database APIs
## Testing
- Add regression tests for CRITICAL-1 and CRITICAL-2
- All 9 existing tests pass
Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>
Dustin-Mike Jens Hähnel