fix(player): 解锁状态登录期内共享，重进播放页不再丢解锁

解锁记录原本是播放页实例的私有集合，退出再进入会先闪一次锁定态，还会
被 selectLocked 提前释放播放器。改为进程内共享的 UnlockedEpisodeRegistry，
由全局注入并在登录态变化时清空；播放器三处渲染分支统一走同一判定，
会话锁态只约束当前页，避免相邻预加载页被误判为锁定。

test/player/player_locked_auth_flow_test.dart

@@ -8,6 +8,7 @@ import 'package:fruitshorts/core/data/repositories/commerce_repository.dart';
 import 'package:fruitshorts/core/data/repositories/playback_repository.dart';
 import 'package:fruitshorts/core/data/services/android_picture_in_picture.dart';
 import 'package:fruitshorts/core/data/services/playback_session.dart';
+import 'package:fruitshorts/core/data/services/unlocked_episode_registry.dart';
 import 'package:fruitshorts/core/data/services/wallet_controller.dart';
 import 'package:fruitshorts/pages/player/player_logic.dart';
 import 'package:fruitshorts/pages/player/player_view.dart';
@@ -120,6 +121,36 @@ void main() {
     logic.dispose();
     await _drain(logic);
   });
+
+  test('should_keep_episode_unlocked_when_reentering_player_page', () async {
+    final registry = UnlockedEpisodeRegistry();
+    registry.markUnlocked('locked-1');
+    final playback = FakePlaybackRepository(
+      ticket: const PlayTicket(
+        episodeId: 'locked-1',
+        accessible: true,
+        accessType: 'ENTITLED',
+        playUrl: '/files/locked-1.mp4',
+      ),
+    );
+    // 重进播放页 = 新建 PlayerLogic，但沿用同一张解锁登记表。
+    final logic = _logic(playback, unlockedEpisodes: registry);
+    logic.attach(
+      const PlayerPage(drama: _lockedDrama, initialIndex: 0),
+      isMounted: () => true,
+    );
+    logic.start(
+      factory: (_) => _NoopPlayer(),
+      coordinator: PlaybackCoordinator(),
+    );
+    await _drain(logic);
+
+    expect(logic.isEpisodeLocked(logic.sessionEpisodes.single), isFalse);
+    expect(logic.session.active, isNotNull);
+
+    logic.dispose();
+    await _drain(logic);
+  });
 }
 
 PlayerLogic _logic(
@@ -127,11 +158,13 @@ PlayerLogic _logic(
   bool signedIn = true,
   bool Function()? isSignedIn,
   WalletController? wallet,
+  UnlockedEpisodeRegistry? unlockedEpisodes,
 }) {
   return PlayerLogic(
     history: FakeWatchHistory(),
     playback: playback,
     wallet: wallet,
+    unlockedEpisodes: unlockedEpisodes,
     pictureInPicture: AndroidPictureInPicture(
       channel: const MethodChannel('test/player_locked_auth_flow/pip'),
     ),