feat: 添加双人对练功能

- 新增数据库迁移脚本 (practice_rooms, practice_room_messages)
- 新增后端 API: 房间创建/加入/消息同步/报告生成
- 新增前端页面: 入口页/对练房间/报告页
- 新增 AI 双人评估服务和提示词

frontend/src/router/index.ts

@@ -120,6 +120,30 @@ const routes: RouteRecordRaw[] = [
         name: 'AIPracticeCoze',
         component: () => import('@/views/trainee/ai-practice-coze.vue'),
         meta: { title: 'AI陪练会话', hidden: true }
+      },
+      {
+        path: 'duo-practice',
+        name: 'DuoPractice',
+        component: () => import('@/views/trainee/duo-practice.vue'),
+        meta: { title: '双人对练', icon: 'Connection' }
+      },
+      {
+        path: 'duo-practice/room/:code',
+        name: 'DuoPracticeRoom',
+        component: () => import('@/views/trainee/duo-practice-room.vue'),
+        meta: { title: '对练房间', hidden: true }
+      },
+      {
+        path: 'duo-practice/join/:code',
+        name: 'DuoPracticeJoin',
+        component: () => import('@/views/trainee/duo-practice-room.vue'),
+        meta: { title: '加入对练', hidden: true }
+      },
+      {
+        path: 'duo-practice/report/:id',
+        name: 'DuoPracticeReport',
+        component: () => import('@/views/trainee/duo-practice-report.vue'),
+        meta: { title: '对练报告', hidden: true }
       }
     ]
   },