refactor: adopt shared mixins, helpers, and sliver widgets

lib/main.dart

@@ -19,6 +19,7 @@ import 'profiles/active_profile_provider.dart';
 import 'profiles/profile.dart';
 import 'profiles/profile_connection_registry.dart';
 import 'profiles/profile_registry.dart';
+import 'mixins/mounted_set_state_mixin.dart';
 import 'profiles/plex_home_service.dart';
 import 'screens/main_screen.dart';
 import 'screens/auth_screen.dart';
@@ -991,7 +992,7 @@ class SetupScreen extends StatefulWidget {
   State<SetupScreen> createState() => _SetupScreenState();
 }
 
-class _SetupScreenState extends State<SetupScreen> {
+class _SetupScreenState extends State<SetupScreen> with MountedSetStateMixin {
   String _statusMessage = '';
 
   // Per-server connection status: serverId -> (name, connected?)
@@ -1004,7 +1005,7 @@ class _SetupScreenState extends State<SetupScreen> {
   }
 
   void _setStatus(String message) {
-    if (mounted) setState(() => _statusMessage = message);
+    setStateIfMounted(() => _statusMessage = message);
   }
 
   Future<void> _loadSavedCredentials() async {

lib/mpv/player/platform/player_android.dart

@@ -1,3 +1,4 @@
+import 'package:collection/collection.dart';
 import 'package:flutter/services.dart';
 
 import '../../models.dart';
@@ -200,10 +201,7 @@ class PlayerAndroid extends PlayerBase {
           final storedId = _hiddenSubtitleTrackId;
           if (storedId != null) {
             _hiddenSubtitleTrackId = null;
-            final track = state.tracks.subtitle.cast<SubtitleTrack?>().firstWhere(
+            final track = state.tracks.subtitle.firstWhereOrNull((t) => t.id == storedId);
-              (t) => t?.id == storedId,
-              orElse: () => null,
-            );
             if (track != null) {
               await selectSubtitleTrack(track);
             }

lib/mpv/player/player_base.dart

@@ -1,6 +1,7 @@
 import 'dart:async';
 import 'dart:convert';
 
+import 'package:collection/collection.dart';
 import 'package:flutter/foundation.dart' show protected;
 import 'package:flutter/services.dart';
 
@@ -267,12 +268,7 @@ abstract class PlayerBase with PlayerStreamControllersMixin implements Player {
 
       case 'audio-device':
         if (value is String && value.isNotEmpty) {
-          final device =
+          final device = _state.audioDevices.firstWhereOrNull((d) => d.name == value) ?? AudioDevice(name: value);
-              _state.audioDevices.cast<AudioDevice?>().firstWhere(
-                (d) => d?.name == value,
-                orElse: () => AudioDevice(name: value),
-              ) ??
-              AudioDevice(name: value);
           _state = _state.copyWith(audioDevice: device);
           audioDeviceController.add(device);
         }
@@ -441,7 +437,7 @@ abstract class PlayerBase with PlayerStreamControllersMixin implements Player {
     AudioTrack? selectedTrack;
 
     if (id != null && id != 'no') {
-      selectedTrack = _state.tracks.audio.cast<AudioTrack?>().firstWhere((t) => t?.id == id, orElse: () => null);
+      selectedTrack = _state.tracks.audio.firstWhereOrNull((t) => t.id == id);
     }
 
     _state = _state.copyWith(track: _state.track.copyWith(audio: selectedTrack));
@@ -454,7 +450,7 @@ abstract class PlayerBase with PlayerStreamControllersMixin implements Player {
 
     selectedTrack = (id == null || id == 'no')
         ? SubtitleTrack.off
-        : _state.tracks.subtitle.cast<SubtitleTrack?>().firstWhere((t) => t?.id == id, orElse: () => null);
+        : _state.tracks.subtitle.firstWhereOrNull((t) => t.id == id);
 
     _state = _state.copyWith(track: _state.track.copyWith(subtitle: selectedTrack));
     trackController.add(_state.track);
@@ -467,7 +463,7 @@ abstract class PlayerBase with PlayerStreamControllersMixin implements Player {
     if (id == null || id == 'no') {
       selectedTrack = null;
     } else {
-      selectedTrack = _state.tracks.subtitle.cast<SubtitleTrack?>().firstWhere((t) => t?.id == id, orElse: () => null);
+      selectedTrack = _state.tracks.subtitle.firstWhereOrNull((t) => t.id == id);
     }
 
     _state = _state.copyWith(track: _state.track.copyWith(secondarySubtitle: selectedTrack));

lib/providers/shader_provider.dart

@@ -1,3 +1,4 @@
+import 'package:collection/collection.dart';
 import 'package:flutter/foundation.dart';
 
 import '../mixins/disposable_change_notifier_mixin.dart';
@@ -67,8 +68,7 @@ class ShaderProvider extends ChangeNotifier with DisposableChangeNotifierMixin {
   bool get isShaderEnabled => _currentPreset.type != ShaderPresetType.none;
 
   ShaderPreset? findPresetById(String id) {
-    return ShaderPreset.fromId(id) ??
+    return ShaderPreset.fromId(id) ?? _customPresets.firstWhereOrNull((p) => p.id == id);
-        _customPresets.cast<ShaderPreset?>().firstWhere((p) => p!.id == id, orElse: () => null);
   }
 
   Future<void> setPreset(ShaderPreset preset) async {

lib/screens/base_media_list_detail_screen.dart

@@ -8,6 +8,7 @@ import '../media/media_server_client.dart';
 import '../providers/multi_server_provider.dart';
 import '../utils/provider_extensions.dart';
 import '../services/media_list_playback_launcher.dart';
+import '../widgets/loading_indicator_box.dart';
 import '../utils/app_logger.dart';
 import '../utils/snackbar_helper.dart';
 import '../mixins/refreshable.dart';
@@ -124,7 +125,7 @@ abstract class BaseMediaListDetailScreen<T extends StatefulWidget> extends State
     }
 
     if (items.isEmpty && isLoading) {
-      return [const SliverFillRemaining(child: Center(child: CircularProgressIndicator()))];
+      return [LoadingIndicatorBox.sliver];
     }
 
     if (items.isEmpty) {

lib/screens/discover_screen.dart

@@ -25,6 +25,7 @@ import '../providers/hidden_libraries_provider.dart';
 import '../providers/libraries_provider.dart';
 import '../providers/playback_state_provider.dart';
 import '../widgets/hub_section.dart';
+import '../widgets/loading_indicator_box.dart';
 import 'profile/profile_switch_screen.dart';
 import '../connection/connection_registry.dart';
 import '../profiles/active_profile_provider.dart';
@@ -53,7 +54,7 @@ import '../utils/platform_detector.dart';
 import '../theme/mono_tokens.dart';
 import '../services/watch_next_service.dart';
 import 'auth_screen.dart';
-import 'libraries/state_messages.dart';
+import 'libraries/content_state_builder.dart';
 import 'main_screen.dart';
 import '../watch_together/watch_together.dart';
 import '../providers/companion_remote_provider.dart';
@@ -1173,15 +1174,8 @@ class _DiscoverScreenState extends State<DiscoverScreen>
                   );
                 },
               ),
-              if (_isLoading) const SliverFillRemaining(child: Center(child: CircularProgressIndicator())),
+              if (_isLoading) LoadingIndicatorBox.sliver,
-              if (_errorMessage != null)
+              if (_errorMessage != null) SliverErrorState(message: _errorMessage!, onRetry: _loadContent),
-                SliverFillRemaining(
-                  child: ErrorStateWidget(
-                    message: _errorMessage!,
-                    icon: Symbols.error_outline_rounded,
-                    onRetry: _loadContent,
-                  ),
-                ),
               if (!_isLoading && _errorMessage == null) ...[
                 // On Deck / Continue Watching
                 if (_onDeck.isNotEmpty)

lib/screens/hub_detail_screen.dart

@@ -11,12 +11,13 @@ import '../utils/provider_extensions.dart';
 import '../widgets/focusable_media_card.dart';
 import '../widgets/media_grid_delegate.dart';
 import '../widgets/desktop_app_bar.dart';
+import '../widgets/loading_indicator_box.dart';
 import '../widgets/overlay_sheet.dart';
 import '../focus/focusable_action_bar.dart';
 import '../focus/key_event_utils.dart';
 import '../mixins/grid_focus_node_mixin.dart';
 import 'libraries/sort_bottom_sheet.dart';
-import 'libraries/state_messages.dart';
+import 'libraries/content_state_builder.dart';
 import '../mixins/refreshable.dart';
 import '../i18n/strings.g.dart';
 import 'focusable_detail_screen_mixin.dart';
@@ -290,15 +291,9 @@ class _HubDetailScreenState extends State<HubDetailScreen>
             slivers: [
               CustomAppBar(title: Text(widget.hub.title), pinned: true, actions: buildFocusableAppBarActions()),
               if (_errorMessage != null)
-                SliverFillRemaining(
+                SliverErrorState(message: _errorMessage!, onRetry: _loadMoreItems)
-                  child: ErrorStateWidget(
-                    message: _errorMessage!,
-                    icon: Symbols.error_outline_rounded,
-                    onRetry: _loadMoreItems,
-                  ),
-                )
               else if (_filteredItems.isEmpty && _isLoading)
-                const SliverFillRemaining(child: Center(child: CircularProgressIndicator()))
+                LoadingIndicatorBox.sliver
               else if (_filteredItems.isEmpty)
                 SliverFillRemaining(child: Center(child: Text(t.hubDetail.noItemsFound)))
               else

lib/screens/libraries/content_state_builder.dart

@@ -3,6 +3,39 @@ import 'package:material_symbols_icons/symbols.dart';
 import '../../i18n/strings.g.dart';
 import 'state_messages.dart';
 
+/// Sliver wrapper around [ErrorStateWidget] for use in `CustomScrollView.slivers`.
+class SliverErrorState extends StatelessWidget {
+  final String message;
+  final VoidCallback? onRetry;
+  final String? retryLabel;
+
+  const SliverErrorState({super.key, required this.message, this.onRetry, this.retryLabel});
+
+  @override
+  Widget build(BuildContext context) => SliverFillRemaining(
+    child: ErrorStateWidget(
+      message: message,
+      icon: Symbols.error_outline_rounded,
+      onRetry: onRetry,
+      retryLabel: retryLabel ?? t.common.retry,
+    ),
+  );
+}
+
+/// Sliver wrapper around [EmptyStateWidget] for use in `CustomScrollView.slivers`.
+class SliverEmptyState extends StatelessWidget {
+  final String message;
+  final IconData icon;
+  final String? subtitle;
+
+  const SliverEmptyState({super.key, required this.message, required this.icon, this.subtitle});
+
+  @override
+  Widget build(BuildContext context) => SliverFillRemaining(
+    child: EmptyStateWidget(message: message, icon: icon, subtitle: subtitle),
+  );
+}
+
 /// A widget that handles loading, error, empty, and content states
 /// Provides a consistent UI pattern across the app for data-driven screens
 class ContentStateBuilder<T> extends StatelessWidget {

lib/screens/libraries/folder_tree_view.dart

@@ -4,6 +4,7 @@ import '../../media/media_item.dart';
 import '../../media/media_kind.dart';
 import '../../services/play_queue_launcher.dart';
 import '../../utils/app_logger.dart';
+import '../../utils/error_message_utils.dart';
 import '../../utils/media_navigation_helper.dart';
 import '../../utils/provider_extensions.dart';
 import '../../utils/snackbar_helper.dart';
@@ -85,9 +86,8 @@ class FolderTreeViewState extends State<FolderTreeView> {
     } catch (e) {
       if (!mounted) return;
 
-      appLogger.e('Failed to load root folders', error: e);
       setState(() {
-        _errorMessage = t.errors.failedToLoad(context: t.libraries.folders, error: e.toString());
+        _errorMessage = mapUnexpectedErrorToMessage(e, context: t.libraries.folders);
         _isLoadingRoot = false;
       });
     }
@@ -130,13 +130,13 @@ class FolderTreeViewState extends State<FolderTreeView> {
     } catch (e) {
       if (!mounted) return;
 
-      appLogger.e('Failed to load folder children', error: e);
+      final message = mapUnexpectedErrorToMessage(e, context: t.libraries.folders);
       setState(() {
         _loadingFolders.remove(folderKey);
       });
 
       if (mounted) {
-        showErrorSnackBar(context, t.errors.failedToLoad(context: t.libraries.folders, error: e.toString()));
+        showErrorSnackBar(context, message);
       }
     }
   }

lib/screens/libraries/tabs/library_browse_tab.dart

@@ -30,6 +30,7 @@ import '../library_alpha_bar_strategy.dart';
 import '../library_filter_sort_loader.dart';
 import '../../../widgets/focusable_media_card.dart';
 import '../../../widgets/focusable_filter_chip.dart';
+import '../../../widgets/loading_indicator_box.dart';
 import '../../../widgets/media_grid_delegate.dart';
 import '../../../widgets/overlay_sheet.dart';
 import '../../../mixins/library_tab_focus_mixin.dart';
@@ -38,7 +39,7 @@ import '../filters_bottom_sheet.dart';
 import '../sort_bottom_sheet.dart';
 import '../../../widgets/app_icon.dart';
 import '../../../widgets/focusable_list_tile.dart';
-import '../state_messages.dart';
+import '../content_state_builder.dart';
 import '../../../services/storage_service.dart';
 import '../../../services/settings_service.dart';
 import '../../../mixins/grid_focus_node_mixin.dart';
@@ -1384,28 +1385,15 @@ class _LibraryBrowseTabState extends BaseLibraryTabState<MediaItem, LibraryBrows
     }
 
     if (isLoading && totalSize == 0 && loadedItems.isEmpty) {
-      return [const SliverFillRemaining(child: Center(child: CircularProgressIndicator()))];
+      return [LoadingIndicatorBox.sliver];
     }
 
     if (errorMessage != null && loadedItems.isEmpty) {
-      return [
+      return [SliverErrorState(message: errorMessage!, onRetry: _loadContent)];
-        SliverFillRemaining(
-          child: ErrorStateWidget(
-            message: errorMessage!,
-            icon: Symbols.error_outline_rounded,
-            onRetry: _loadContent,
-            retryLabel: t.common.retry,
-          ),
-        ),
-      ];
     }
 
     if (totalSize == 0 && !isLoading) {
-      return [
+      return [SliverEmptyState(message: t.libraries.thisLibraryIsEmpty, icon: Symbols.folder_open_rounded)];
-        SliverFillRemaining(
-          child: EmptyStateWidget(message: t.libraries.thisLibraryIsEmpty, icon: Symbols.folder_open_rounded),
-        ),
-      ];
     }
 
     return [

lib/screens/livetv/live_tv_show_schedule_screen.dart

@@ -6,12 +6,14 @@ import '../../focus/focusable_action_bar.dart';
 import '../../focus/focusable_wrapper.dart';
 import '../../i18n/strings.g.dart';
 import '../../models/livetv_channel.dart';
+import '../../mixins/mounted_set_state_mixin.dart';
 import '../../models/livetv_program.dart';
 import '../../providers/multi_server_provider.dart';
 import '../../theme/mono_tokens.dart';
 import '../../utils/formatters.dart';
 import '../../widgets/app_icon.dart';
 import '../../widgets/focused_scroll_scaffold.dart';
+import '../../widgets/loading_indicator_box.dart';
 import '../../widgets/overlay_sheet.dart';
 import 'live_tv_actions_mixin.dart';
 import 'livetv_recording_actions.dart';
@@ -34,7 +36,7 @@ class LiveTvShowScheduleScreen extends StatefulWidget {
 }
 
 class _LiveTvShowScheduleScreenState extends State<LiveTvShowScheduleScreen>
-    with LiveTvActionsMixin<LiveTvShowScheduleScreen> {
+    with LiveTvActionsMixin<LiveTvShowScheduleScreen>, MountedSetStateMixin {
   List<LiveTvProgram> _programs = [];
   bool _isLoading = true;
 
@@ -51,7 +53,7 @@ class _LiveTvShowScheduleScreenState extends State<LiveTvShowScheduleScreen>
     final multiServer = context.read<MultiServerProvider>();
     final genericClient = multiServer.getClientForServer(widget.serverId);
     if (genericClient == null) {
-      if (mounted) setState(() => _isLoading = false);
+      setStateIfMounted(() => _isLoading = false);
       return;
     }
 
@@ -128,7 +130,7 @@ class _LiveTvShowScheduleScreenState extends State<LiveTvShowScheduleScreen>
             : null,
         slivers: [
           if (_isLoading)
-            const SliverFillRemaining(child: Center(child: CircularProgressIndicator()))
+            LoadingIndicatorBox.sliver
           else if (_programs.isEmpty)
             SliverFillRemaining(child: Center(child: Text(t.liveTv.noPrograms)))
           else

lib/screens/livetv/program_details_sheet.dart

@@ -5,6 +5,7 @@ import 'package:material_symbols_icons/symbols.dart';
 import '../../focus/focusable_button.dart';
 import '../../i18n/strings.g.dart';
 import '../../media/media_server_client.dart';
+import '../../mixins/mounted_set_state_mixin.dart';
 import '../../models/livetv_channel.dart';
 import '../../models/livetv_program.dart';
 import '../../models/media_subscription.dart';
@@ -79,7 +80,7 @@ class _ProgramDetailsSheetContent extends StatefulWidget {
   State<_ProgramDetailsSheetContent> createState() => _ProgramDetailsSheetContentState();
 }
 
-class _ProgramDetailsSheetContentState extends State<_ProgramDetailsSheetContent> {
+class _ProgramDetailsSheetContentState extends State<_ProgramDetailsSheetContent> with MountedSetStateMixin {
   final List<FocusNode> _focusNodes = [];
   MediaSubscription? _existingSubscription;
   bool _checkedMapping = false;
@@ -115,7 +116,7 @@ class _ProgramDetailsSheetContentState extends State<_ProgramDetailsSheetContent
     final providerId = widget.program.providerIdentifier;
     final ratingKey = widget.program.ratingKey;
     if (client == null || providerId == null || providerId.isEmpty || ratingKey == null || ratingKey.isEmpty) {
-      if (mounted) setState(() => _checkedMapping = true);
+      setStateIfMounted(() => _checkedMapping = true);
       return;
     }
     try {
@@ -129,7 +130,7 @@ class _ProgramDetailsSheetContentState extends State<_ProgramDetailsSheetContent
     } catch (e) {
       // 403 (no DVR access) or transient — treat as unscheduled.
       appLogger.d('Subscription mapping check failed: $e');
-      if (mounted) setState(() => _checkedMapping = true);
+      setStateIfMounted(() => _checkedMapping = true);
     }
   }
 

lib/screens/livetv/record_options_sheet.dart

@@ -8,6 +8,7 @@ import '../../focus/focusable_text_field.dart';
 import '../../focus/focusable_wrapper.dart';
 import '../../i18n/strings.g.dart';
 import '../../media/media_server_client.dart';
+import '../../mixins/controller_disposer_mixin.dart';
 import '../../models/livetv_program.dart';
 import '../../models/media_subscription.dart';
 import '../../utils/app_logger.dart';
@@ -472,13 +473,13 @@ class _IntSettingRow extends StatefulWidget {
   State<_IntSettingRow> createState() => _IntSettingRowState();
 }
 
-class _IntSettingRowState extends State<_IntSettingRow> {
+class _IntSettingRowState extends State<_IntSettingRow> with ControllerDisposerMixin {
   late final TextEditingController _controller;
 
   @override
   void initState() {
     super.initState();
-    _controller = TextEditingController(text: widget.currentValue?.toString() ?? '');
+    _controller = createTextEditingController(text: widget.currentValue?.toString() ?? '');
   }
 
   @override
@@ -488,12 +489,6 @@ class _IntSettingRowState extends State<_IntSettingRow> {
     if (next != _controller.text) _controller.text = next;
   }
 
-  @override
-  void dispose() {
-    _controller.dispose();
-    super.dispose();
-  }
-
   @override
   Widget build(BuildContext context) {
     final theme = Theme.of(context);
@@ -542,13 +537,13 @@ class _TextSettingRow extends StatefulWidget {
   State<_TextSettingRow> createState() => _TextSettingRowState();
 }
 
-class _TextSettingRowState extends State<_TextSettingRow> {
+class _TextSettingRowState extends State<_TextSettingRow> with ControllerDisposerMixin {
   late final TextEditingController _controller;
 
   @override
   void initState() {
     super.initState();
-    _controller = TextEditingController(text: widget.currentValue?.toString() ?? '');
+    _controller = createTextEditingController(text: widget.currentValue?.toString() ?? '');
   }
 
   @override
@@ -558,12 +553,6 @@ class _TextSettingRowState extends State<_TextSettingRow> {
     if (next != _controller.text) _controller.text = next;
   }
 
-  @override
-  void dispose() {
-    _controller.dispose();
-    super.dispose();
-  }
-
   @override
   Widget build(BuildContext context) {
     final theme = Theme.of(context);

lib/screens/livetv/tabs/guide_tab.dart

@@ -10,6 +10,7 @@ import '../../../focus/dpad_navigator.dart';
 import '../../../focus/input_mode_tracker.dart';
 import '../../../focus/key_event_utils.dart';
 import '../../../i18n/strings.g.dart';
+import '../../../mixins/mounted_set_state_mixin.dart';
 import '../../../models/livetv_channel.dart';
 import '../../../models/livetv_program.dart';
 import '../../../providers/multi_server_provider.dart';
@@ -45,7 +46,7 @@ class GuideTab extends StatefulWidget {
 
 enum _GuideZone { timeNav, grid }
 
-class GuideTabState extends State<GuideTab> {
+class GuideTabState extends State<GuideTab> with MountedSetStateMixin {
   static const _slotWidth = 180.0;
   static const _channelColumnWidth = 100.0;
   static const _rowHeight = 64.0;
@@ -111,7 +112,7 @@ class GuideTabState extends State<GuideTab> {
 
     _timeIndicatorTimer = Timer.periodic(const Duration(minutes: 1), (_) {
       // ignore: no-empty-block - setState triggers rebuild to update time indicator
-      if (mounted) setState(() {});
+      setStateIfMounted(() {});
     });
   }
 
@@ -121,7 +122,7 @@ class GuideTabState extends State<GuideTab> {
     _timeIndicatorTimer?.cancel();
     _timeIndicatorTimer = Timer.periodic(const Duration(minutes: 1), (_) {
       // ignore: no-empty-block - setState triggers rebuild to update time indicator
-      if (mounted) setState(() {});
+      setStateIfMounted(() {});
     });
   }
 

lib/screens/livetv/tabs/whats_on_tab.dart

@@ -10,6 +10,7 @@ import '../../../focus/key_event_utils.dart';
 import '../../../focus/locked_hub_controller.dart';
 import '../../../i18n/strings.g.dart';
 import '../../../media/media_item_types.dart';
+import '../../../mixins/mounted_set_state_mixin.dart';
 import '../../../models/livetv_channel.dart';
 import '../../../models/livetv_hub_result.dart';
 import '../../../providers/multi_server_provider.dart';
@@ -39,7 +40,7 @@ class WhatsOnTab extends StatefulWidget {
   State<WhatsOnTab> createState() => WhatsOnTabState();
 }
 
-class WhatsOnTabState extends State<WhatsOnTab> with LiveTvActionsMixin<WhatsOnTab> {
+class WhatsOnTabState extends State<WhatsOnTab> with LiveTvActionsMixin<WhatsOnTab>, MountedSetStateMixin {
   List<LiveTvHubResult> _hubs = [];
   bool _isLoading = true;
   Timer? _refreshTimer;
@@ -104,7 +105,7 @@ class WhatsOnTabState extends State<WhatsOnTab> with LiveTvActionsMixin<WhatsOnT
       });
     } catch (e) {
       appLogger.e('Failed to load live TV hubs', error: e);
-      if (mounted) setState(() => _isLoading = false);
+      setStateIfMounted(() => _isLoading = false);
     }
   }
 
@@ -223,7 +224,7 @@ class _LiveTvHubSection extends StatefulWidget {
   State<_LiveTvHubSection> createState() => _LiveTvHubSectionState();
 }
 
-class _LiveTvHubSectionState extends State<_LiveTvHubSection> {
+class _LiveTvHubSectionState extends State<_LiveTvHubSection> with MountedSetStateMixin {
   static const _longPressDuration = Duration(milliseconds: 500);
 
   late FocusNode _hubFocusNode;
@@ -271,7 +272,7 @@ class _LiveTvHubSectionState extends State<_LiveTvHubSection> {
       _longPressTriggered = false;
     }
     // ignore: no-empty-block - setState triggers rebuild to update focus styling
-    if (mounted) setState(() {});
+    setStateIfMounted(() {});
   }
 
   void requestFocusAt(int index) {
@@ -283,7 +284,7 @@ class _LiveTvHubSectionState extends State<_LiveTvHubSection> {
     _scrollToIndex(clamped);
     _hubFocusNode.requestFocus();
     // ignore: no-empty-block - setState triggers rebuild to update focus styling
-    if (mounted) setState(() {});
+    setStateIfMounted(() {});
     _scrollHubIntoView();
   }
 

lib/screens/main_screen.dart

@@ -18,6 +18,7 @@ import '../utils/snackbar_helper.dart';
 import '../utils/update_dialog.dart';
 import '../utils/video_player_navigation.dart';
 import '../main.dart';
+import '../mixins/mounted_set_state_mixin.dart';
 import '../mixins/refreshable.dart';
 import '../widgets/overlay_sheet.dart';
 import '../mixins/tab_visibility_aware.dart';
@@ -96,7 +97,8 @@ class MainScreen extends StatefulWidget {
   State<MainScreen> createState() => _MainScreenState();
 }
 
-class _MainScreenState extends State<MainScreen> with RouteAware, WindowListener, WidgetsBindingObserver {
+class _MainScreenState extends State<MainScreen>
+    with RouteAware, WindowListener, WidgetsBindingObserver, MountedSetStateMixin {
   NavigationTabId _currentTab = NavigationTabId.discover;
   String? _selectedLibraryGlobalKey;
 
@@ -797,7 +799,7 @@ class _MainScreenState extends State<MainScreen> with RouteAware, WindowListener
         await serverManager.checkServerHealth();
         await serverManager.reconnectOfflineServers(forceRediscovery: true);
       } finally {
-        if (mounted) setState(() => _isReconnecting = false);
+        setStateIfMounted(() => _isReconnecting = false);
       }
     }());
   }

lib/screens/media_detail_screen.dart

@@ -1848,6 +1848,19 @@ class _MediaDetailScreenState extends State<MediaDetailScreen>
     return Symbols.recommend_rounded;
   }
 
+  static const Widget _sectionLoading = Center(
+    child: Padding(padding: EdgeInsets.all(32), child: CircularProgressIndicator()),
+  );
+
+  Widget _sectionEmpty(BuildContext context, String message) {
+    return Padding(
+      padding: const EdgeInsets.all(32),
+      child: Center(
+        child: Text(message, style: Theme.of(context).textTheme.bodyLarge?.copyWith(color: Colors.grey)),
+      ),
+    );
+  }
+
   /// Build episode list directly when the library hides seasons for single-season shows
   Widget _buildEpisodesList() {
     final client = _getMediaClientForMetadata(context);
@@ -2217,19 +2230,9 @@ class _MediaDetailScreenState extends State<MediaDetailScreen>
                           if (isShow && !_showEpisodesDirectly) ...[
                             // Season tabs + inline episodes
                             if (_isLoadingSeasons)
-                              const Center(
+                              _sectionLoading
-                                child: Padding(padding: EdgeInsets.all(32), child: CircularProgressIndicator()),
-                              )
                             else if (_seasons.isEmpty)
-                              Padding(
+                              _sectionEmpty(context, t.messages.noSeasonsFound)
-                                padding: const EdgeInsets.all(32),
-                                child: Center(
-                                  child: Text(
-                                    t.messages.noSeasonsFound,
-                                    style: theme.textTheme.bodyLarge?.copyWith(color: Colors.grey),
-                                  ),
-                                ),
-                              )
                             else ...[
                               Text(
                                 key: _seasonsSectionKey,
@@ -2240,21 +2243,11 @@ class _MediaDetailScreenState extends State<MediaDetailScreen>
                               _buildSeasonTabs(),
                               const SizedBox(height: 16),
                               if (_isLoadingSeasonEpisodes)
-                                const Center(
+                                _sectionLoading
-                                  child: Padding(padding: EdgeInsets.all(32), child: CircularProgressIndicator()),
-                                )
                               else if (_episodes.isNotEmpty)
                                 _buildEpisodesList()
                               else
-                                Padding(
+                                _sectionEmpty(context, t.messages.noEpisodesFoundGeneral),
-                                  padding: const EdgeInsets.all(32),
-                                  child: Center(
-                                    child: Text(
-                                      t.messages.noEpisodesFoundGeneral,
-                                      style: theme.textTheme.bodyLarge?.copyWith(color: Colors.grey),
-                                    ),
-                                  ),
-                                ),
                             ],
                             const SizedBox(height: 24),
                           ] else if ((isShow && _showEpisodesDirectly) || metadata.isSeason) ...[
@@ -2266,21 +2259,11 @@ class _MediaDetailScreenState extends State<MediaDetailScreen>
                             ),
                             const SizedBox(height: 12),
                             if (_isLoadingSeasons || _isLoadingEpisodes)
-                              const Center(
+                              _sectionLoading
-                                child: Padding(padding: EdgeInsets.all(32), child: CircularProgressIndicator()),
-                              )
                             else if (_episodes.isNotEmpty)
                               _buildEpisodesList()
                             else
-                              Padding(
+                              _sectionEmpty(context, t.messages.noEpisodesFoundGeneral),
-                                padding: const EdgeInsets.all(32),
-                                child: Center(
-                                  child: Text(
-                                    t.messages.noEpisodesFoundGeneral,
-                                    style: theme.textTheme.bodyLarge?.copyWith(color: Colors.grey),
-                                  ),
-                                ),
-                              ),
                             const SizedBox(height: 24),
                           ],
 

lib/screens/plex_metadata_edit_screen.dart

@@ -7,6 +7,7 @@ import '../media/media_kind.dart';
 import '../services/plex_client.dart';
 import '../utils/app_logger.dart';
 import '../utils/dialogs.dart';
+import '../utils/formatters.dart';
 import '../utils/language_codes.dart';
 import '../utils/provider_extensions.dart';
 import '../utils/snackbar_helper.dart';
@@ -269,8 +270,7 @@ class _PlexMetadataEditScreenState extends State<PlexMetadataEditScreen> {
 
     if (picked != null && mounted) {
       setState(() {
-        _originallyAvailableAt =
+        _originallyAvailableAt = '${picked.year}-${padNumber(picked.month, 2)}-${padNumber(picked.day, 2)}';
-            '${picked.year}-${picked.month.toString().padLeft(2, '0')}-${picked.day.toString().padLeft(2, '0')}';
       });
     }
   }
@@ -456,10 +456,7 @@ class _PlexMetadataEditScreenState extends State<PlexMetadataEditScreen> {
   @override
   Widget build(BuildContext context) {
     if (_isLoading) {
-      return FocusedScrollScaffold(
+      return FocusedScrollScaffold(title: Text(t.metadataEdit.screenTitle), slivers: [LoadingIndicatorBox.sliver]);
-        title: Text(t.metadataEdit.screenTitle),
-        slivers: [const SliverFillRemaining(child: Center(child: CircularProgressIndicator()))],
-      );
     }
 
     return FocusedScrollScaffold(

lib/screens/profile/borrow_connection_screen.dart

@@ -23,6 +23,7 @@ import '../../utils/app_logger.dart';
 import '../../utils/snackbar_helper.dart';
 import '../../widgets/app_icon.dart';
 import '../../widgets/backend_badge.dart';
+import '../../widgets/loading_indicator_box.dart';
 import '../../widgets/desktop_app_bar.dart';
 import '../libraries/state_messages.dart';
 import 'pin_entry_dialog.dart';
@@ -175,7 +176,7 @@ class _BorrowConnectionScreenState extends State<BorrowConnectionScreen> {
                 ),
               ),
               if (snapshot.connectionState != ConnectionState.done)
-                const SliverFillRemaining(child: Center(child: CircularProgressIndicator()))
+                LoadingIndicatorBox.sliver
               else if (candidates.isEmpty)
                 SliverFillRemaining(
                   child: EmptyStateWidget(

lib/screens/profile/profile_switch_screen.dart

@@ -9,6 +9,7 @@ import '../../connection/connection_registry.dart';
 import '../../focus/focusable_wrapper.dart';
 import '../../i18n/strings.g.dart';
 import '../../media/media_backend.dart';
+import '../../mixins/mounted_set_state_mixin.dart';
 import '../../profiles/active_profile_binder.dart';
 import '../../profiles/active_profile_provider.dart';
 import '../../profiles/plex_home_service.dart';
@@ -47,7 +48,7 @@ class ProfileSwitchScreen extends StatefulWidget {
   State<ProfileSwitchScreen> createState() => _ProfileSwitchScreenState();
 }
 
-class _ProfileSwitchScreenState extends State<ProfileSwitchScreen> {
+class _ProfileSwitchScreenState extends State<ProfileSwitchScreen> with MountedSetStateMixin {
   bool _allowPop = false;
   final FocusNode _firstSelectableFocusNode = FocusNode();
   bool _focusRequested = false;
@@ -68,7 +69,7 @@ class _ProfileSwitchScreenState extends State<ProfileSwitchScreen> {
     if (_storage == null) {
       unawaited(
         StorageService.getInstance().then((s) {
-          if (mounted) setState(() => _storage = s);
+          setStateIfMounted(() => _storage = s);
         }),
       );
     }
@@ -351,7 +352,7 @@ class _ProfileSwitchScreenState extends State<ProfileSwitchScreen> {
       }
       navigator.pop(true);
     } finally {
-      if (mounted) setState(() => _switching = false);
+      setStateIfMounted(() => _switching = false);
     }
   }
 }

lib/screens/search_screen.dart

@@ -13,6 +13,7 @@ import '../providers/multi_server_provider.dart';
 import '../utils/app_logger.dart';
 import '../utils/snackbar_helper.dart';
 import '../widgets/desktop_app_bar.dart';
+import '../widgets/loading_indicator_box.dart';
 import '../widgets/pill_input_decoration.dart';
 import '../widgets/focusable_media_card.dart';
 import '../utils/focus_utils.dart';
@@ -232,7 +233,7 @@ class _SearchScreenState extends State<SearchScreen>
               ),
             ),
             if (_isSearching)
-              const SliverFillRemaining(child: Center(child: CircularProgressIndicator()))
+              LoadingIndicatorBox.sliver
             else if (!_hasSearched)
               SliverFillRemaining(
                 child: StateMessageWidget(

lib/screens/settings/licenses_screen.dart

@@ -3,6 +3,7 @@ import 'package:flutter/material.dart';
 import 'package:plezy/widgets/app_icon.dart';
 import 'package:material_symbols_icons/symbols.dart';
 import '../../widgets/focused_scroll_scaffold.dart';
+import '../../widgets/loading_indicator_box.dart';
 import '../../i18n/strings.g.dart';
 
 class MergedLicenseEntry {
@@ -52,10 +53,7 @@ class LicensesScreen extends StatelessWidget {
       builder: (context, snapshot) {
         final mergedLicenses = snapshot.data;
         if (mergedLicenses == null) {
-          return FocusedScrollScaffold(
+          return FocusedScrollScaffold(title: Text(t.screens.licenses), slivers: [LoadingIndicatorBox.sliver]);
-            title: Text(t.screens.licenses),
-            slivers: const [SliverFillRemaining(child: Center(child: CircularProgressIndicator()))],
-          );
         }
 
         return FocusedScrollScaffold(

lib/screens/settings/logs_screen.dart

@@ -13,9 +13,11 @@ import '../../focus/focusable_action_bar.dart';
 import '../../focus/focusable_button.dart';
 import '../../focus/key_event_utils.dart';
 import '../../i18n/strings.g.dart';
+import '../../mixins/mounted_set_state_mixin.dart';
 import '../../utils/dialogs.dart';
 import '../../main.dart' show gitCommit;
 import '../../utils/app_logger.dart';
+import '../../utils/formatters.dart';
 import '../../utils/platform_detector.dart';
 import '../../utils/snackbar_helper.dart';
 import '../../widgets/desktop_app_bar.dart';
@@ -27,7 +29,7 @@ class LogsScreen extends StatefulWidget {
   State<LogsScreen> createState() => _LogsScreenState();
 }
 
-class _LogsScreenState extends State<LogsScreen> {
+class _LogsScreenState extends State<LogsScreen> with MountedSetStateMixin {
   List<LogEntry> _logs = [];
   String _deviceInfo = '';
   final ScrollController _scrollController = ScrollController();
@@ -64,7 +66,7 @@ class _LogsScreenState extends State<LogsScreen> {
       buffer.writeln('Linux ${info.versionId ?? info.id}');
     }
 
-    if (mounted) setState(() => _deviceInfo = buffer.toString().trimRight());
+    setStateIfMounted(() => _deviceInfo = buffer.toString().trimRight());
   }
 
   @override
@@ -80,10 +82,10 @@ class _LogsScreenState extends State<LogsScreen> {
   }
 
   String _formatTime(DateTime time) {
-    final hour = time.hour.toString().padLeft(2, '0');
+    final hour = padNumber(time.hour, 2);
-    final minute = time.minute.toString().padLeft(2, '0');
+    final minute = padNumber(time.minute, 2);
-    final second = time.second.toString().padLeft(2, '0');
+    final second = padNumber(time.second, 2);
-    final millisecond = time.millisecond.toString().padLeft(3, '0');
+    final millisecond = padNumber(time.millisecond, 3);
     return '$hour:$minute:$second.$millisecond';
   }
 

lib/screens/settings/settings_screen.dart

@@ -14,6 +14,7 @@ import '../../focus/focusable_text_field.dart';
 import '../../focus/input_mode_tracker.dart';
 import '../../i18n/strings.g.dart';
 import '../main_screen.dart';
+import '../../mixins/mounted_set_state_mixin.dart';
 import '../../mixins/refreshable.dart';
 import '../../providers/hidden_libraries_provider.dart';
 import '../../providers/libraries_provider.dart';
@@ -57,7 +58,7 @@ class SettingsScreen extends StatefulWidget {
   State<SettingsScreen> createState() => _SettingsScreenState();
 }
 
-class _SettingsScreenState extends State<SettingsScreen> with FocusableTab {
+class _SettingsScreenState extends State<SettingsScreen> with FocusableTab, MountedSetStateMixin {
   late final FocusMemoryTracker _focusTracker;
 
   // Focus tracking keys
@@ -95,13 +96,13 @@ class _SettingsScreenState extends State<SettingsScreen> with FocusableTab {
     _focusTracker = FocusMemoryTracker(
       onFocusChanged: () {
         // ignore: no-empty-block - setState triggers rebuild to update focus styling
-        if (mounted) setState(() {});
+        setStateIfMounted(() {});
       },
       debugLabelPrefix: 'settings',
     );
     if (_keyboardShortcutsSupported) {
       KeyboardShortcutsService.getInstance().then((s) {
-        if (mounted) setState(() => _keyboardService = s);
+        setStateIfMounted(() => _keyboardService = s);
       });
     }
   }

lib/services/jellyfin_client.dart

@@ -94,8 +94,7 @@ class JellyfinClient with MediaServerCacheMixin implements MediaServerClient, Sc
     // leak the token verbatim. `LogRedactionManager.redact()` also has
     // pattern-based fallbacks for `api_key=`, `X-Emby-Token`, and the
     // `Authorization: MediaBrowser ... Token="..."` header.
-    LogRedactionManager.registerServerUrl(connection.baseUrl);
+    LogRedactionManager.registerServer(connection.baseUrl, connection.accessToken);
-    LogRedactionManager.registerToken(connection.accessToken);
     String version = '1.0';
     try {
       final pkg = await PackageInfo.fromPlatform();

lib/services/jellyfin_media_info_mapper.dart

@@ -1,3 +1,5 @@
+import 'package:collection/collection.dart';
+
 import '../media/media_version.dart';
 import '../media/media_source_info.dart';
 import '../utils/jellyfin_time.dart';
@@ -197,7 +199,7 @@ Map<int, TrickplayInfo>? _parseTrickplayManifest(Object? raw, String? sourceId)
       // Source id not in the manifest — fall back to the first nested
       // entry so the user still gets *something*. The caller already
       // chose the right source; this is best-effort recovery.
-      final first = raw.values.cast<Object?>().firstWhere((v) => v is Map, orElse: () => null);
+      final first = raw.values.firstWhereOrNull((v) => v is Map);
       if (first is! Map) return null;
       resolutionMap = first;
     }

lib/services/plex_client.dart

@@ -248,8 +248,7 @@ class PlexClient with MediaServerCacheMixin, _PlexLiveTvClientMethods implements
            : null,
        _onEndpointChanged = onEndpointChanged,
        _onAllEndpointsExhausted = onAllEndpointsExhausted {
-    LogRedactionManager.registerServerUrl(config.baseUrl);
+    LogRedactionManager.registerServer(config.baseUrl, config.token);
-    LogRedactionManager.registerToken(config.token);
 
     _http = MediaServerHttpClient(
       baseUrl: config.baseUrl,

lib/services/settings_export_service.dart

@@ -9,6 +9,7 @@ import 'package:path_provider/path_provider.dart';
 import 'package:shared_preferences/shared_preferences.dart';
 
 import '../utils/app_logger.dart';
+import '../utils/formatters.dart';
 import '../utils/platform_detector.dart';
 import 'file_picker_service.dart';
 import 'settings_service.dart';
@@ -271,9 +272,9 @@ class SettingsExportService {
 
   static Future<String> _defaultFileName() async {
     final now = DateTime.now();
-    final y = now.year.toString().padLeft(4, '0');
+    final y = padNumber(now.year, 4);
-    final m = now.month.toString().padLeft(2, '0');
+    final m = padNumber(now.month, 2);
-    final d = now.day.toString().padLeft(2, '0');
+    final d = padNumber(now.day, 2);
     return 'plezy-settings-$y$m$d.$fileExtension';
   }
 

lib/services/shader_asset_loader.dart

@@ -3,6 +3,7 @@ import 'dart:io';
 import 'package:flutter/services.dart';
 import 'package:path/path.dart' as path;
 import 'package:path_provider/path_provider.dart';
+import 'package:uuid/uuid.dart';
 
 import '../models/shader_preset.dart';
 import '../utils/app_logger.dart';
@@ -211,7 +212,7 @@ class ShaderAssetLoader {
   static Future<String> importCustomShader(String sourcePath) async {
     final customDir = await _getCustomShaderDirectory();
     final ext = path.extension(sourcePath);
-    final uuid = DateTime.now().millisecondsSinceEpoch.toRadixString(36);
+    final uuid = const Uuid().v4();
     final storedName = '$uuid$ext';
     final targetFile = File(path.join(customDir, storedName));
 

lib/utils/log_redaction_manager.dart

@@ -85,6 +85,14 @@ class LogRedactionManager {
     _rebuildCombinedPattern();
   }
 
+  /// Convenience: register a server's URL and access token together.
+  /// Call this before any HTTP traffic so the very first probe URL doesn't
+  /// leak credentials verbatim.
+  static void registerServer(String? url, String? token) {
+    registerServerUrl(url);
+    registerToken(token);
+  }
+
   /// Register other sensitive values that need redaction.
   static void registerCustomValue(String? value) {
     final normalized = _normalize(value);

lib/watch_together/screens/watch_together_screen.dart

@@ -7,6 +7,7 @@ import 'package:material_symbols_icons/symbols.dart';
 import 'package:provider/provider.dart';
 
 import '../../i18n/strings.g.dart';
+import '../../mixins/mounted_set_state_mixin.dart';
 import '../../focus/focusable_button.dart';
 import '../../focus/focusable_text_field.dart';
 import '../../focus/focusable_wrapper.dart';
@@ -74,7 +75,7 @@ class _NotInSessionView extends StatefulWidget {
   State<_NotInSessionView> createState() => _NotInSessionViewState();
 }
 
-class _NotInSessionViewState extends State<_NotInSessionView> {
+class _NotInSessionViewState extends State<_NotInSessionView> with MountedSetStateMixin {
   bool _isCreating = false;
   bool _isJoining = false;
   String? _enteringRoomCode;
@@ -218,7 +219,7 @@ class _NotInSessionViewState extends State<_NotInSessionView> {
         displayName: _plexDisplayName,
       );
       await RecentRoomsService.addOrUpdateRoom(sessionId, controlMode: controlMode);
-      if (mounted) setState(() => _recentRooms = RecentRoomsService.getRecentRooms());
+      setStateIfMounted(() => _recentRooms = RecentRoomsService.getRecentRooms());
     } catch (e) {
       appLogger.e('Failed to create session', error: e);
       if (mounted) {
@@ -262,7 +263,7 @@ class _NotInSessionViewState extends State<_NotInSessionView> {
     try {
       await widget.watchTogether.joinSession(sessionId, displayName: _plexDisplayName);
       await RecentRoomsService.addOrUpdateRoom(sessionId);
-      if (mounted) setState(() => _recentRooms = RecentRoomsService.getRecentRooms());
+      setStateIfMounted(() => _recentRooms = RecentRoomsService.getRecentRooms());
     } catch (e) {
       appLogger.e('Failed to join session', error: e);
       if (mounted) {
@@ -285,7 +286,7 @@ class _NotInSessionViewState extends State<_NotInSessionView> {
         displayName: _plexDisplayName,
       );
       await RecentRoomsService.addOrUpdateRoom(room.code);
-      if (mounted) setState(() => _recentRooms = RecentRoomsService.getRecentRooms());
+      setStateIfMounted(() => _recentRooms = RecentRoomsService.getRecentRooms());
     } catch (e) {
       appLogger.e('Failed to enter room', error: e);
       if (mounted) {

lib/widgets/companion_remote/discovery_view.dart

@@ -7,6 +7,7 @@ import '../../connection/connection_registry.dart';
 import '../../focus/focusable_text_field.dart';
 import '../../i18n/strings.g.dart';
 import '../../mixins/controller_disposer_mixin.dart';
+import '../../mixins/mounted_set_state_mixin.dart';
 import '../../models/plex/plex_home.dart';
 import '../../profiles/active_plex_identity.dart';
 import '../../profiles/active_profile_provider.dart';
@@ -24,7 +25,7 @@ class DiscoveryView extends StatefulWidget {
   State<DiscoveryView> createState() => _DiscoveryViewState();
 }
 
-class _DiscoveryViewState extends State<DiscoveryView> with ControllerDisposerMixin {
+class _DiscoveryViewState extends State<DiscoveryView> with ControllerDisposerMixin, MountedSetStateMixin {
   late final _hostAddressController = createTextEditingController();
   final _formKey = GlobalKey<FormState>();
   bool _isConnecting = false;
@@ -127,7 +128,7 @@ class _DiscoveryViewState extends State<DiscoveryView> with ControllerDisposerMi
       if (!mounted) return;
       setState(() => _errorMessage = _parseErrorMessage(e.toString()));
     } finally {
-      if (mounted) setState(() => _isConnecting = false);
+      setStateIfMounted(() => _isConnecting = false);
     }
   }
 

lib/widgets/companion_remote/remote_session_dialog.dart

@@ -3,6 +3,7 @@ import 'package:provider/provider.dart';
 
 import '../../connection/connection_registry.dart';
 import '../../i18n/strings.g.dart';
+import '../../mixins/mounted_set_state_mixin.dart';
 import '../../profiles/active_plex_identity.dart';
 import '../../profiles/active_profile_provider.dart';
 import '../../profiles/plex_home_service.dart';
@@ -27,7 +28,7 @@ class RemoteSessionDialog extends StatefulWidget {
   }
 }
 
-class _RemoteSessionDialogState extends State<RemoteSessionDialog> {
+class _RemoteSessionDialogState extends State<RemoteSessionDialog> with MountedSetStateMixin {
   bool _isStarting = false;
   String? _errorMessage;
 
@@ -78,7 +79,7 @@ class _RemoteSessionDialogState extends State<RemoteSessionDialog> {
         await provider.startHostServer();
       }
 
-      if (mounted) setState(() => _isStarting = false);
+      setStateIfMounted(() => _isStarting = false);
     } catch (e) {
       appLogger.e('Failed to start companion remote server', error: e);
       if (!mounted) return;

lib/widgets/hub_section.dart

@@ -14,6 +14,7 @@ import '../utils/grid_size_calculator.dart';
 import '../theme/mono_tokens.dart';
 import '../focus/locked_hub_controller.dart';
 import '../media/media_hub.dart';
+import '../mixins/mounted_set_state_mixin.dart';
 import '../screens/hub_detail_screen.dart';
 import '../utils/media_navigation_helper.dart';
 import 'focus_builders.dart';
@@ -76,7 +77,7 @@ class HubSection extends StatefulWidget {
   State<HubSection> createState() => HubSectionState();
 }
 
-class HubSectionState extends State<HubSection> {
+class HubSectionState extends State<HubSection> with MountedSetStateMixin {
   static const _longPressDuration = Duration(milliseconds: 500);
 
   late FocusNode _hubFocusNode;
@@ -130,7 +131,7 @@ class HubSectionState extends State<HubSection> {
       _longPressTriggered = false;
     }
     // ignore: no-empty-block - setState triggers rebuild to update focus styling
-    if (mounted) setState(() {});
+    setStateIfMounted(() {});
   }
 
   /// Request focus on this hub at a specific item index
@@ -144,7 +145,7 @@ class HubSectionState extends State<HubSection> {
     _scrollToIndex(clamped);
     _hubFocusNode.requestFocus();
     // ignore: no-empty-block - setState triggers rebuild to update focus styling
-    if (mounted) setState(() {});
+    setStateIfMounted(() {});
 
     _scrollHubIntoView();
   }

lib/widgets/loading_indicator_box.dart

@@ -12,6 +12,11 @@ class LoadingIndicatorBox extends StatelessWidget {
   final double size;
   const LoadingIndicatorBox({super.key, this.size = 18});
 
+  /// Full-screen centered spinner sized to fill the remaining space inside a
+  /// [CustomScrollView]. Replaces inline
+  /// `SliverFillRemaining(child: Center(child: CircularProgressIndicator()))`.
+  static const Widget sliver = SliverFillRemaining(child: Center(child: CircularProgressIndicator()));
+
   @override
   Widget build(BuildContext context) =>
       SizedBox(width: size, height: size, child: const CircularProgressIndicator(strokeWidth: 2));

lib/widgets/side_navigation_rail.dart

@@ -10,6 +10,7 @@ import 'package:provider/provider.dart';
 import '../focus/dpad_navigator.dart';
 import '../focus/focus_memory_tracker.dart';
 import '../media/media_library.dart';
+import '../mixins/mounted_set_state_mixin.dart';
 import '../navigation/navigation_tabs.dart';
 import '../providers/hidden_libraries_provider.dart';
 import '../providers/libraries_provider.dart';
@@ -186,7 +187,7 @@ class SideNavigationRail extends StatefulWidget {
   State<SideNavigationRail> createState() => SideNavigationRailState();
 }
 
-class SideNavigationRailState extends State<SideNavigationRail> {
+class SideNavigationRailState extends State<SideNavigationRail> with MountedSetStateMixin {
   bool _librariesExpanded = true;
 
   bool _isHovered = false;
@@ -225,7 +226,7 @@ class SideNavigationRailState extends State<SideNavigationRail> {
     _focusTracker = FocusMemoryTracker(
       onFocusChanged: () {
         // ignore: no-empty-block - setState triggers rebuild to update focus styling
-        if (mounted) setState(() {});
+        setStateIfMounted(() {});
       },
       debugLabelPrefix: 'nav',
     );

lib/widgets/tv_virtual_keyboard.dart

@@ -4,6 +4,7 @@ import 'package:material_symbols_icons/symbols.dart';
 
 import '../focus/dpad_navigator.dart';
 import '../i18n/strings.g.dart';
+import '../mixins/mounted_set_state_mixin.dart';
 import '../utils/platform_detector.dart';
 
 Future<void> showTvVirtualKeyboard({
@@ -85,7 +86,7 @@ class _TvVirtualKeyboardDialog extends StatefulWidget {
   State<_TvVirtualKeyboardDialog> createState() => _TvVirtualKeyboardDialogState();
 }
 
-class _TvVirtualKeyboardDialogState extends State<_TvVirtualKeyboardDialog> {
+class _TvVirtualKeyboardDialogState extends State<_TvVirtualKeyboardDialog> with MountedSetStateMixin {
   static const double _keySize = 60;
   static const double _keyGap = 6;
   static const double _rowGap = 6;
@@ -115,7 +116,7 @@ class _TvVirtualKeyboardDialogState extends State<_TvVirtualKeyboardDialog> {
   }
 
   void _handleTextChanged() {
-    if (mounted) setState(() {});
+    setStateIfMounted(() {});
   }
 
   bool get _isNumberKeyboard {