feat: A3-A6 数据层（内容/播放/记录收藏/互动的 HTTP 对接）

- AppCatalog 模型（feed/section/card/detail/episode/banner/category）
- HttpCatalogRepository 对接首页/发现/分类/详情
- PlaybackRepository 播放票据、WatchRepository 记录收藏
- InteractionRepository 评论点赞举报、WalletRepository 钱包解锁

lib/core/data/repositories/http_catalog_repository.dart

@@ -0,0 +1,33 @@
+// Author: fruit.com.cn
+
+import '../models/app_catalog.dart';
+import '../services/api_client.dart';
+
+/// 对接后端 `/app/**` 内容接口（A3）。
+class HttpCatalogRepository {
+  HttpCatalogRepository(this._client);
+
+  final ApiClient _client;
+
+  Future<AppFeed> fetchHomeFeed() async {
+    final data = await _client.get('/app/home/feed');
+    return AppFeed.fromJson(data as Map<String, dynamic>);
+  }
+
+  Future<AppFeed> fetchDiscoverFeed() async {
+    final data = await _client.get('/app/discover/feed');
+    return AppFeed.fromJson(data as Map<String, dynamic>);
+  }
+
+  Future<List<AppCategory>> fetchCategories() async {
+    final data = await _client.get('/app/categories');
+    return (data as List)
+        .map((e) => AppCategory.fromJson(e as Map<String, dynamic>))
+        .toList();
+  }
+
+  Future<AppDramaDetail> fetchDramaDetail(int id) async {
+    final data = await _client.get('/app/dramas/$id');
+    return AppDramaDetail.fromJson(data as Map<String, dynamic>);
+  }
+}

lib/core/data/repositories/interaction_repository.dart

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+// Author: fruit.com.cn
+
+import '../services/api_client.dart';
+
+/// 评论、点赞、举报（A6）。
+class InteractionRepository {
+  InteractionRepository(this._client);
+
+  final ApiClient _client;
+
+  Future<void> postComment({
+    required int dramaId,
+    required String content,
+    int? rootId,
+  }) async {
+    await _client.post('/app/comments', data: {
+      'dramaId': dramaId,
+      'content': content,
+      if (rootId != null) 'rootId': rootId,
+    });
+  }
+
+  Future<List<dynamic>> fetchComments({
+    required int dramaId,
+    int? cursor,
+    int size = 20,
+  }) async {
+    final data = await _client.get('/app/comments', query: {
+      'dramaId': dramaId,
+      if (cursor != null) 'cursor': cursor,
+      'size': size,
+    });
+    return data as List;
+  }
+
+  Future<void> deleteComment(int id) async {
+    await _client.delete('/app/comments/$id');
+  }
+
+  Future<void> toggleLike({
+    required String targetType,
+    required int targetId,
+  }) async {
+    await _client.post('/app/likes/toggle', data: {
+      'targetType': targetType,
+      'targetId': targetId,
+    });
+  }
+
+  Future<void> report({
+    required String targetType,
+    required int targetId,
+    required String reason,
+  }) async {
+    await _client.post('/app/reports', data: {
+      'targetType': targetType,
+      'targetId': targetId,
+      'reason': reason,
+    });
+  }
+}

lib/core/data/repositories/playback_repository.dart

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+// Author: fruit.com.cn
+
+import '../services/api_client.dart';
+
+/// 播放票据（A4）。
+class PlaybackRepository {
+  PlaybackRepository(this._client);
+
+  final ApiClient _client;
+
+  /// 签发播放票据与签名地址，客户端原样使用 playUrl。
+  Future<Map<String, dynamic>> fetchPlayTicket(int episodeId) async {
+    final data = await _client.get('/app/episodes/$episodeId/play');
+    return data as Map<String, dynamic>;
+  }
+}

lib/core/data/repositories/wallet_repository.dart

@@ -0,0 +1,25 @@
+// Author: fruit.com.cn
+
+import '../services/api_client.dart';
+
+/// 钱包、金币解锁（09 收费支付）。
+class WalletRepository {
+  WalletRepository(this._client);
+
+  final ApiClient _client;
+
+  Future<Map<String, dynamic>> fetchWallet() async {
+    final data = await _client.get('/app/wallet');
+    return data as Map<String, dynamic>;
+  }
+
+  Future<Map<String, dynamic>> unlockEpisode(int episodeId) async {
+    final data = await _client.post('/app/episodes/$episodeId/unlock');
+    return data as Map<String, dynamic>;
+  }
+
+  Future<List<dynamic>> fetchOrders() async {
+    final data = await _client.get('/app/orders');
+    return data as List;
+  }
+}

lib/core/data/repositories/watch_repository.dart

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+// Author: fruit.com.cn
+
+import '../services/api_client.dart';
+
+/// 观看记录与收藏（A5）。
+class WatchRepository {
+  WatchRepository(this._client);
+
+  final ApiClient _client;
+
+  Future<void> reportProgress({
+    required int episodeId,
+    required int positionSec,
+    required int durationSec,
+  }) async {
+    await _client.post('/app/watch/progress', data: {
+      'episodeId': episodeId,
+      'positionSec': positionSec,
+      'durationSec': durationSec,
+    });
+  }
+
+  Future<Map<String, dynamic>> fetchProgress(int dramaId) async {
+    final data = await _client.get('/app/watch/progress', query: {
+      'dramaId': dramaId,
+    });
+    return data as Map<String, dynamic>;
+  }
+
+  Future<List<dynamic>> fetchRecent({int limit = 20}) async {
+    final data = await _client.get('/app/watch/recent', query: {'limit': limit});
+    return data as List;
+  }
+
+  Future<void> deleteProgress(int dramaId) async {
+    await _client.delete('/app/watch/progress/$dramaId');
+  }
+
+  Future<void> clearProgress() async {
+    await _client.delete('/app/watch/progress');
+  }
+
+  Future<bool> toggleFavorite(int dramaId) async {
+    final data = await _client.post('/app/favorites/toggle', data: {
+      'dramaId': dramaId,
+    });
+    final map = data as Map<String, dynamic>;
+    return map['favorited'] as bool? ?? false;
+  }
+
+  Future<List<dynamic>> fetchFavorites() async {
+    final data = await _client.get('/app/favorites');
+    return data as List;
+  }
+
+  Future<void> deleteFavorite(int dramaId) async {
+    await _client.delete('/app/favorites/$dramaId');
+  }
+}