fix(player): 修复切集返回推荐页黑屏

lib/core/data/services/playback_queue.dart

@@ -4,6 +4,9 @@ import '../models/drama.dart';
 
 /// A player session has one navigation meaning: browse dramas or browse episodes.
 class PlaybackQueue {
+  PlaybackQueue.fromEntries(List<PlaybackEntry> entries)
+    : entries = List.unmodifiable(entries);
+
   PlaybackQueue.home(List<Drama> dramas)
     : entries = List.unmodifiable(
         dramas

lib/core/data/services/playback_session.dart

@@ -137,6 +137,47 @@ class PlaybackSession extends ChangeNotifier {
     if (_visible && !_overlayOpen) _warmNeighbors(this);
   }
 
+  /// 在剧维度和集维度之间切换队列，但保留当前 active controller 与播放状态。
+  void remapQueuePreservingActive(
+    List<Episode> nextEpisodes, {
+    required int currentIndex,
+    int? preloadIndex,
+    int? previousIndex,
+    bool notify = true,
+  }) {
+    if (_closed ||
+        currentIndex < 0 ||
+        currentIndex >= nextEpisodes.length ||
+        _active == null) {
+      return;
+    }
+    _generation++;
+    episodes
+      ..clear()
+      ..addAll(nextEpisodes);
+    _active!.index = currentIndex;
+    _currentIndex = currentIndex;
+    _selected = true;
+    _loading = false;
+    _error = null;
+    _rememberNeighbors(preloadIndex, previousIndex);
+    final staleNext = _next;
+    final stalePrevious = _previous;
+    final staleHandoff = _handoff;
+    _next = null;
+    _previous = null;
+    _handoff = null;
+    if (notify) _notify();
+    unawaited(
+      _enqueue(() async {
+        await _retire(staleNext);
+        await _retire(stalePrevious);
+        await _retire(staleHandoff);
+      }),
+    );
+    if (_visible && !_overlayOpen) _warmNeighbors(this);
+  }
+
   void _rememberNeighbors(int? preloadIndex, int? previousIndex) {
     _nextIndex = preloadIndex;
     _previousIndex = previousIndex;