feat(ui): add Mornye glass theme and adaptive music player

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.

lib/services/library_database.dart

@@ -77,16 +77,21 @@ class LibraryDatabase {
         columns: ['id', 'path'],
         where: localSources,
       );
+      final localSourceIds = sources.map((source) => source['id']).toSet();
       final rows = await txn.query(
         'library',
-        columns: ['id', 'file_path', 'cover_path'],
-        where:
-            'source_id IN (SELECT id FROM library_sources WHERE $localSources)',
+        columns: ['id', 'source_id', 'file_path', 'cover_path'],
       );
       final batch = txn.batch();
       for (final row in rows) {
         final updates = <String, Object?>{};
         for (final column in ['file_path', 'cover_path']) {
+          // Bookmarks own external audio paths, but extracted covers always
+          // live in our sandbox, including covers from bookmarked folders.
+          if (column == 'file_path' &&
+              !localSourceIds.contains(row['source_id'])) {
+            continue;
+          }
           final previous = row[column] as String?;
           if (previous == null) continue;
           final current = rebaseIosSandboxPath(previous, documents.path);