feat: M1.1 完成 + M1.2 启动 — 全量更新

M1.1 收尾:
- 24项 P0/P1/P2 bug 修复 (Rust 107 tests + Flutter 15 tests)
- Flutter App v0.3: cupertino_icons 修复, 单元测试, 调试面板, APK 52.6MB
- 示例插件完善: manifest.json + 请求/响应示范 + 7个测试
- API 文档重写 (以 routes.rs 为唯一权威)
- MILESTONES.md 更新至 100%

M1.2 启动:
- P0: 插件管理 API 闭环 (handle_manager_message Custom 分支 + broadcast_plugin_states)
- ServiceManager 集成测试 8/8 (tests/m1_2_service_manager.rs)
- M1.2 测试计划 (docs/M1.2_TEST_PLAN.md, 18个E2E场景)
- 动态插件系统: auto_rollback + version_manager GC + 路径穿越防护

总计: Rust 115/115 测试, Flutter 15/15 测试, 零 warning

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

clients/flutter/lib/screens/playback_screen.dart

@@ -29,9 +29,12 @@ class _PlaybackScreenState extends State<PlaybackScreen> {
 
     return Scaffold(
       appBar: AppBar(title: const Text('播放控制')),
-      body: ListView(
-        padding: const EdgeInsets.all(AppSpacing.md),
-        children: [
+      body: RefreshIndicator(
+        onRefresh: _handleRefresh,
+        child: ListView(
+          physics: const AlwaysScrollableScrollPhysics(),
+          padding: const EdgeInsets.all(AppSpacing.md),
+          children: [
           Card(
             child: Padding(
               padding: const EdgeInsets.all(AppSpacing.lg),
@@ -164,11 +167,20 @@ class _PlaybackScreenState extends State<PlaybackScreen> {
               ),
             );
           }),
-        ],
+          ],
+        ),
       ),
     );
   }
 
+  Future<void> _handleRefresh() async {
+    final provider = context.read<PlayerProvider>();
+    await Future.wait<void>([
+      provider.fetchStatus(),
+      provider.fetchPlaylist(),
+    ]);
+  }
+
   void _handleGoto() {
     final index = int.tryParse(_indexController.text.trim());
     if (index == null) {