fix(library): sync track playback controls

test/music_player_provider_test.dart

@@ -0,0 +1,38 @@
+import 'package:audio_service/audio_service.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:spotiflac_android/providers/music_player_provider.dart';
+
+void main() {
+  test('Library playback state follows only the current media item', () async {
+    final container = ProviderContainer(
+      overrides: [
+        currentMediaItemProvider.overrideWith(
+          (ref) =>
+              Stream.value(const MediaItem(id: 'track-1', title: 'Track 1')),
+        ),
+        playbackPlayingProvider.overrideWith((ref) => true),
+        playbackLoadingProvider.overrideWith((ref) => false),
+      ],
+    );
+    addTearDown(container.dispose);
+    final currentMediaSubscription = container.listen(
+      currentMediaItemProvider,
+      (_, _) {},
+    );
+    addTearDown(currentMediaSubscription.close);
+
+    await container.read(currentMediaItemProvider.future);
+
+    expect(container.read(mediaItemPlaybackUiProvider('track-1')), (
+      isCurrent: true,
+      isPlaying: true,
+      isLoading: false,
+    ));
+    expect(container.read(mediaItemPlaybackUiProvider('track-2')), (
+      isCurrent: false,
+      isPlaying: false,
+      isLoading: false,
+    ));
+  });
+}

test/queue_library_refresh_policy_test.dart

@@ -407,12 +407,13 @@ void main() {
     expect(gridSource, contains('CompletionBridgePlayableStatus.checking'));
     expect(gridSource, contains('semanticsLabel:'));
     expect(gridSource, contains('queueCheckingDownloadedFile'));
-    expect(gridSource, contains('TrackGridPlayButton('));
+    expect(gridSource, contains('_LibraryPlaybackButton('));
+    expect(gridSource, contains('grid: true'));
     expect(listSource, contains('resolveCompletionBridgePlayablePath('));
     expect(listSource, contains('_completionBridgePlayableProbe.listenable('));
     expect(listSource, contains('CompletionBridgePlayableStatus.checking'));
     expect(listSource, contains('semanticsLabel:'));
     expect(listSource, contains('queueCheckingDownloadedFile'));
-    expect(listSource, contains('Icons.play_arrow'));
+    expect(listSource, contains('_LibraryPlaybackButton('));
   });
 }