perf(library): lazy-load collections and dispose queries

lib/screens/library_tracks_folder_screen.dart

@@ -58,6 +58,19 @@ class _LibraryTracksFolderScreenState
         CollapsingHeaderScrollMixin<LibraryTracksFolderScreen> {
   UserPlaylistCollection? playlist;
 
+  @override
+  void initState() {
+    super.initState();
+    final playlistId = widget.playlistId;
+    if (widget.mode == LibraryTracksFolderMode.playlist && playlistId != null) {
+      Future.microtask(
+        () => ref
+            .read(libraryCollectionsProvider.notifier)
+            .ensurePlaylistLoaded(playlistId),
+      );
+    }
+  }
+
   IconData _modeIcon() {
     return switch (widget.mode) {
       LibraryTracksFolderMode.wishlist => Icons.bookmark,

lib/screens/queue_tab_collection_items.dart

@@ -482,7 +482,7 @@ extension _QueueTabCollectionItemWidgets on _QueueTabState {
                       colorScheme,
                     ),
                     title: playlist.name,
-                    count: playlist.tracks.length,
+                    count: playlist.trackCount,
                     onTap: _isPlaylistSelectionMode
                         ? () => _togglePlaylistSelection(playlist.id)
                         : () => _openPlaylistById(playlist.id),
@@ -630,7 +630,7 @@ extension _QueueTabCollectionItemWidgets on _QueueTabState {
                       ),
                       title: playlist.name,
                       subtitle:
-                          '${playlist.tracks.length} ${playlist.tracks.length == 1 ? 'track' : 'tracks'}',
+                          '${playlist.trackCount} ${playlist.trackCount == 1 ? 'track' : 'tracks'}',
                       onTap: _isPlaylistSelectionMode
                           ? () => _togglePlaylistSelection(playlist.id)
                           : () => _openPlaylistById(playlist.id),
@@ -646,5 +646,4 @@ extension _QueueTabCollectionItemWidgets on _QueueTabState {
         );
     }
   }
-
 }

lib/screens/queue_tab_helpers.dart

@@ -262,8 +262,8 @@ class _QueueLibraryPageData {
   }
 }
 
-final _queueLibraryPageProvider =
-    FutureProvider.family<_QueueLibraryPageData, _QueueLibraryPageRequest>((
+final _queueLibraryPageProvider = FutureProvider.autoDispose
+    .family<_QueueLibraryPageData, _QueueLibraryPageRequest>((
       ref,
       request,
     ) async {
@@ -338,8 +338,8 @@ final _queueLibraryPageProvider =
       );
     });
 
-final _queueLibraryCountsProvider =
-    FutureProvider.family<QueueLibraryCounts, _QueueLibraryCountsRequest>((
+final _queueLibraryCountsProvider = FutureProvider.autoDispose
+    .family<QueueLibraryCounts, _QueueLibraryCountsRequest>((
       ref,
       request,
     ) async {

lib/screens/queue_tab_navigation.dart

@@ -382,10 +382,14 @@ extension _QueueTabNavigation on _QueueTabState {
       );
     }
 
-    final firstCoverUrl = playlist.tracks
-        .where((e) => e.track.coverUrl != null && e.track.coverUrl!.isNotEmpty)
-        .map((e) => e.track.coverUrl!)
-        .firstOrNull;
+    final firstCoverUrl =
+        playlist.tracks
+            .where(
+              (e) => e.track.coverUrl != null && e.track.coverUrl!.isNotEmpty,
+            )
+            .map((e) => e.track.coverUrl!)
+            .firstOrNull ??
+        playlist.previewCover;
 
     if (firstCoverUrl != null) {
       // Guard against local file paths that may have been stored as coverUrl

lib/screens/queue_tab_selection.dart

@@ -189,13 +189,13 @@ extension _QueueTabSelectionActions on _QueueTabState {
 
   Future<void> _downloadAllSelectedPlaylists(BuildContext context) async {
     final collectionsState = ref.read(libraryCollectionsProvider);
-    final selectedPlaylists = collectionsState.playlists
+    var selectedPlaylists = collectionsState.playlists
         .where((p) => _selectedPlaylistIds.contains(p.id))
         .toList();
 
     final totalTracks = selectedPlaylists.fold<int>(
       0,
-      (sum, p) => sum + p.tracks.length,
+      (sum, p) => sum + p.trackCount,
     );
 
     if (totalTracks == 0) {
@@ -230,6 +230,18 @@ extension _QueueTabSelectionActions on _QueueTabState {
 
     if (confirmed != true || !context.mounted) return;
 
+    await ref
+        .read(libraryCollectionsProvider.notifier)
+        .ensurePlaylistsLoaded(
+          selectedPlaylists.map((playlist) => playlist.id),
+        );
+    if (!context.mounted) return;
+    selectedPlaylists = ref
+        .read(libraryCollectionsProvider)
+        .playlists
+        .where((playlist) => _selectedPlaylistIds.contains(playlist.id))
+        .toList(growable: false);
+
     final settings = ref.read(settingsProvider);
     final extensionState = ref.read(extensionProvider);
     final queueNotifier = ref.read(downloadQueueProvider.notifier);