fix(player): preserve shader toggle preset

close #1208

lib/providers/shader_provider.dart

@@ -74,9 +74,10 @@ class ShaderProvider extends ChangeNotifier with DisposableChangeNotifierMixin {
   Future<void> setPreset(ShaderPreset preset) async {
     final service = _settingsService ?? await SettingsService.getInstance();
     await service.write(SettingsService.globalShaderPreset, preset.id);
-    if (_savedPresetListenable == null) {
-      _savedPreset = preset;
-      _currentPreset = preset;
+    final changed = _savedPreset.id != preset.id || _currentPreset.id != preset.id;
+    _savedPreset = preset;
+    _currentPreset = preset;
+    if (changed || _savedPresetListenable == null) {
       safeNotifyListeners();
     }
   }

lib/widgets/video_controls/parts/track_controls.dart

@@ -44,7 +44,11 @@ extension _PlexVideoControlsTrackMethods on _PlexVideoControlsState {
           .applyPreset(targetPreset)
           .then((_) async {
             if (!mounted) return;
-            await shaderProvider.setPreset(targetPreset);
+            if (targetPreset.isEnabled) {
+              await shaderProvider.setPreset(targetPreset);
+            } else {
+              shaderProvider.setCurrentPreset(targetPreset);
+            }
             if (!mounted) return;
             // ignore: no-empty-block - setState triggers rebuild to reflect shader changes
             _setControlsState(() {});

test/providers/shader_provider_test.dart

@@ -89,6 +89,23 @@ void main() {
       p.dispose();
     });
 
+    test('setPreset restores current when saved preset id is unchanged', () async {
+      final p = ShaderProvider();
+      await Future.delayed(Duration.zero);
+      final saved = ShaderPreset.anime4kPreset(Anime4KQuality.fast, Anime4KMode.modeA);
+
+      await p.setPreset(saved);
+      p.setCurrentPreset(ShaderPreset.none);
+      expect(p.savedPreset, saved);
+      expect(p.currentPreset, ShaderPreset.none);
+
+      await p.setPreset(saved);
+      expect(p.savedPreset, saved);
+      expect(p.currentPreset, saved);
+
+      p.dispose();
+    });
+
     test('reset returns to the none preset', () async {
       final p = ShaderProvider();
       await Future.delayed(Duration.zero);