播放页部分调整，完整播放链路层级已打通

lib/pages/playlist_page.dart

@@ -4,7 +4,12 @@ import 'package:provider/provider.dart';
 import '../services/audio_service.dart';
 
 class PlaylistPage extends StatelessWidget {
-  const PlaylistPage({super.key});
+  final VoidCallback onClose;
+
+  const PlaylistPage({
+    super.key,
+    required this.onClose,
+  });
 
   @override
   Widget build(BuildContext context) {
@@ -28,7 +33,7 @@ class PlaylistPage extends StatelessWidget {
         foregroundColor: Colors.white,
         leading: IconButton(
           icon: const Icon(Icons.arrow_back_ios_new),
-          onPressed: () => Navigator.pop(context),
+          onPressed: onClose,
         ),
         actions: [
           IconButton(
@@ -55,7 +60,7 @@ class PlaylistPage extends StatelessWidget {
                       onPressed: () {
                         service.clearQueue();
                         Navigator.pop(context);
-                        Navigator.pop(context);
+                        onClose();
                       },
                       child: const Text(
                         '清空',
@@ -141,7 +146,7 @@ class PlaylistPage extends StatelessWidget {
                       : null,
                   onTap: () {
                     service.setQueue(queue, startIndex: index);
-                    Navigator.pop(context);
+                    onClose();
                   },
                 );
               },