feat(player): 切集刷新互动计数统计

lib/core/data/repositories/playback_repository.dart

@@ -1,5 +1,6 @@
 // Author: fruit.com.cn
 
+import '../models/episode_stats.dart';
 import '../models/play_ticket.dart';
 import '../remote/playback_api.dart';
 
@@ -10,6 +11,9 @@ import '../remote/playback_api.dart';
 abstract interface class PlaybackRepository {
   Future<PlayTicket> ticketFor(String episodeId, {bool forceRefresh = false});
 
+  /// 读取互动计数快照；与 [ticketFor] 分离，避免为了刷新计数重新签发地址。
+  Future<EpisodeStats> episodeStats(String episodeId);
+
   /// 当前缓存的票据是否还在有效期内（用于"回前台发现过期就重新取"）。
   bool isFresh(String episodeId);
 }
@@ -42,6 +46,10 @@ class HttpPlaybackRepository implements PlaybackRepository {
     return ticket;
   }
 
+  @override
+  Future<EpisodeStats> episodeStats(String episodeId) =>
+      _api.episodeStats(episodeId);
+
   @override
   bool isFresh(String episodeId) {
     final cached = _cache[episodeId];
@@ -65,11 +73,22 @@ class _CachedTicket {
 
 /// 测试与离线场景用：按集返回固定票据，并记录被请求过几次。
 class FakePlaybackRepository implements PlaybackRepository {
-  FakePlaybackRepository({this.ticket, this.error, this.fresh = true});
+  FakePlaybackRepository({
+    this.ticket,
+    this.error,
+    this.fresh = true,
+    this.stats,
+    this.statsError,
+    Map<String, EpisodeStats>? statsByEpisode,
+  }) : statsByEpisode = statsByEpisode ?? {};
 
   PlayTicket? ticket;
   Object? error;
+  EpisodeStats? stats;
+  Object? statsError;
+  final Map<String, EpisodeStats> statsByEpisode;
   final List<String> requests = [];
+  final List<String> statsRequests = [];
   final List<bool> forced = [];
 
   /// 模拟"票据是否还有效"：置 false 可验证回前台会重新取。
@@ -95,4 +114,13 @@ class FakePlaybackRepository implements PlaybackRepository {
           qualities: const ['AUTO', '720P', '1080P'],
         );
   }
+
+  @override
+  Future<EpisodeStats> episodeStats(String episodeId) async {
+    statsRequests.add(episodeId);
+    if (statsError != null) throw statsError!;
+    final value = statsByEpisode[episodeId] ?? stats;
+    if (value != null) return value;
+    throw StateError('episode stats not configured for $episodeId');
+  }
 }