Add a selectable Mornye theme with shared glass controls, dialogs, sheets, notifications, and collection headers while retaining Material components.
Update player artwork, lyrics transitions and highlighting, synchronized rolling time labels, volume controls, and compact navigation. Unify metadata, Library, search, and extension surfaces; preserve restored artwork and report extension load failures.
Validation: full Flutter analyzer clean; 713 tests passed and 4 skipped; pinned Dart formatting and diff checks passed; signed ARM64 and ARM32 release APKs built and verified.
- album/playlist/library-folder/track-metadata adopt
CollapsingHeaderScrollMixin; artist/library-folder adopt
SelectionModeMixin
- HeaderCircleButton and HeaderMetaRow replace per-screen copies
in album and playlist headers; dead _tallHeader flag removed
- SelectionBottomBar gains optional subtitle labels and backs the
playlist selection bar in queue tab
Single homes for logic that was copy-pasted across screens: the settings
collapsing header, album detail header (online screen's design as the
reference), selection pill button + bottom-bar chrome, disc separator
chip, error card, cover URL upgrade, byte/clock formatting, duration
extraction, UnifiedLibraryItem (moved out of the queue_tab library so
other screens can import it), and the batch convert/ReplayGain engine
keyed on it.