🦞 飞行侠实现：主持龙虾生成纪要

核心功能:
- Meeting 模型：添加 host_agent_id, host_instance_id
- 会议纪要 API：记录获取 + 纪要上传 + 结束通知
- 会议结束自动通知主持龙虾生成纪要
- 平台留存纪要供参会者下载

API 端点:
- GET  /api/v1/meetings/{id}/records/ - 获取会议记录（主持专用）
- POST /api/v1/meetings/{id}/minutes/upload/ - 上传纪要（主持专用）
- POST /api/v1/meetings/{id}/end-notify/ - 会议结束通知

测试:
- test_host_minutes.py: 完整流程测试通过

算力分配:
- 中央平台：消息路由 + 数据存储（轻量级）
- 主持龙虾：生成纪要（消耗用户算力）
- 平台留存：纪要供所有参会者下载

backend/meeting_room/urls.py

@@ -5,6 +5,7 @@ from rest_framework.routers import DefaultRouter
 from meetings.views import MeetingViewSet, ParticipantViewSet
 from users.views import LoginView, RegisterView
 from instances.views import InstanceRegisterView, MeetingJoinView, InstanceListView, WebhookNotifyView
+from meetings.minutes_api import MeetingRecordsView, MinutesUploadView, MeetingEndNotifyView
 
 router = DefaultRouter()
 router.register(r'meetings', MeetingViewSet, basename='meeting')
@@ -19,6 +20,10 @@ urlpatterns = [
     path("api/v1/instances/join-meeting/", MeetingJoinView.as_view()),
     path("api/v1/instances/", InstanceListView.as_view()),
     path("api/v1/instances/webhook-test/", WebhookNotifyView.as_view()),
+    # 会议纪要 API（主持龙虾专用）
+    path("api/v1/meetings/<uuid:pk>/records/", MeetingRecordsView.as_view()),
+    path("api/v1/meetings/<uuid:pk>/minutes/upload/", MinutesUploadView.as_view()),
+    path("api/v1/meetings/<uuid:pk>/end-notify/", MeetingEndNotifyView.as_view()),
     re_path(r'^api/v1/meetings/(?P<pk>[^/.]+)/generate-minutes/$', MeetingViewSet.as_view({'get': 'minutes'}), name='meeting-minutes'),
     path("api/v1/", include(router.urls)),
 ]