fix(player): 修复清晰度切换闪屏与还原黑屏

lib/pages/player/widgets/player_render_stack.dart

@@ -53,12 +53,16 @@ class PlayerRenderStack extends StatefulWidget {
     required this.pageController,
     required this.slots,
     this.onCurrentVideoVisible,
+    this.resumeSignal = 0,
   });
 
   final PageController pageController;
   final Map<PlayerRenderSlotRole, PlayerRenderSlotData> slots;
   final ValueChanged<int?>? onCurrentVideoVisible;
 
+  /// iOS 画中画还原的恢复信号，透传给每个槽位的视频表面。
+  final int resumeSignal;
+
   @override
   State<PlayerRenderStack> createState() => _PlayerRenderStackState();
 }
@@ -200,6 +204,7 @@ class _PlayerRenderStackState extends State<PlayerRenderStack> {
           onVideoVisible: slot.role == PlayerRenderSlotRole.current
               ? () => widget.onCurrentVideoVisible?.call(slot.index)
               : null,
+          resumeSignal: widget.resumeSignal,
         ),
       ),
     );