feat: AI聊天室多Agent协作讨论平台

- 实现Agent管理，支持AI辅助生成系统提示词
- 支持多个AI提供商（OpenRouter、智谱、MiniMax等）
- 实现聊天室和讨论引擎
- WebSocket实时消息推送
- 前端使用React + Ant Design
- 后端使用FastAPI + MongoDB

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

backend/models/__init__.py

@@ -0,0 +1,25 @@
+"""
+数据模型模块
+"""
+from .ai_provider import AIProvider, ProxyConfig, RateLimit
+from .agent import Agent, AgentCapabilities, AgentBehavior
+from .chatroom import ChatRoom, ChatRoomConfig
+from .message import Message, MessageType
+from .discussion_result import DiscussionResult
+from .agent_memory import AgentMemory, MemoryType
+
+__all__ = [
+    "AIProvider",
+    "ProxyConfig", 
+    "RateLimit",
+    "Agent",
+    "AgentCapabilities",
+    "AgentBehavior",
+    "ChatRoom",
+    "ChatRoomConfig",
+    "Message",
+    "MessageType",
+    "DiscussionResult",
+    "AgentMemory",
+    "MemoryType",
+]