- Extract normalizeOptionalString() to lib/utils/string_utils.dart from download_queue_provider and track_metadata_screen
- Extract PrioritySettingsScaffold widget from lyrics and metadata priority pages, reducing ~280 lines of duplication
- Extract _ensureDefaultDocumentsOutputDir/_ensureDefaultAndroidMusicOutputDir in download queue provider
- Extract collectLibraryAudioFiles() and applyDefaultLibraryMetadata() in Go library_scan.go
- Extract plainTextLyricsLines() in Go lyrics.go, used by Apple Music, Musixmatch, and QQ Music clients