feat: C3 客户端埋点 SDK（EventTracker 批量上报 + 核心事件）

lib/app.dart

@@ -41,6 +41,7 @@ import 'core/data/services/download_controller.dart';
 import 'core/data/services/favorite_controller.dart';
 import 'core/data/services/interaction_controller.dart';
 import 'core/data/services/locale_controller.dart';
+import 'core/data/services/event_tracker.dart';
 import 'core/data/services/playback_session.dart';
 import 'core/data/services/video_player_port.dart';
 import 'core/data/services/wallet_controller.dart';
@@ -235,6 +236,7 @@ class _LumaDramaAppState extends State<LumaDramaApp> {
     return MultiProvider(
       providers: [
         Provider(create: (_) => PlaybackCoordinator()),
+        Provider<EventTracker>(create: (_) => EventTracker(_apiClient)),
         Provider<PlayerFactory>(create: (_) => widget.playerFactory),
         Provider<CatalogRepository>.value(value: _catalogRepository),
         Provider<PlaybackRepository>.value(value: _playback),