feat(light): 添加信息灯牌功能及相关组件

- 新增light路由模块，提供灯牌脚本和答案的API接口
- 添加MongoDB连接工具类，支持异步和同步操作
- 实现灯牌服务层，包含数据缓存逻辑
- 移除数据库日志功能，简化日志模块
- 更新依赖项，添加starlette、anyio等MongoDB相关包

src/utils/mongodb.py

@@ -0,0 +1,95 @@
+import os
+import asyncio
+import logging
+from motor.motor_asyncio import AsyncIOMotorClient, AsyncIOMotorDatabase
+from pymongo import MongoClient
+
+# 配置日志
+logger = logging.getLogger(__name__)
+
+# 从环境变量获取MongoDB配置
+MONGODB_URI = os.getenv("MONGODB_URI", "mongodb://localhost:27017")
+MONGODB_DATABASE = os.getenv("MONGODB_DATABASE", "default_db")
+
+class MongoDB:
+    """MongoDB连接管理类"""
+    _client: AsyncIOMotorClient = None
+    _sync_client: MongoClient = None
+    _db: AsyncIOMotorDatabase = None
+    _initialized: bool = False
+    _sync_initialized: bool = False
+    
+    @classmethod
+    async def initialize(cls):
+        """初始化MongoDB连接（异步）"""
+        if cls._initialized:
+            return
+            
+        try:
+            cls._client = AsyncIOMotorClient(MONGODB_URI)
+            cls._db = cls._client[MONGODB_DATABASE]
+            
+            # 验证连接
+            await cls._client.server_info()
+            logger.info("MongoDB异步连接成功")
+            cls._initialized = True
+        except Exception as e:
+            logger.error(f"MongoDB异步连接失败: {str(e)}")
+            raise
+    
+    @classmethod
+    def initialize_sync(cls):
+        """初始化MongoDB连接（同步）"""
+        if cls._sync_initialized:
+            return
+            
+        try:
+            cls._sync_client = MongoClient(MONGODB_URI)
+            # 验证连接
+            cls._sync_client.server_info()
+            logger.info("MongoDB同步连接成功")
+            cls._sync_initialized = True
+        except Exception as e:
+            logger.error(f"MongoDB同步连接失败: {str(e)}")
+            raise
+    
+    @classmethod
+    def get_db(cls) -> AsyncIOMotorDatabase:
+        """获取异步数据库实例"""
+        if not cls._initialized:
+            raise RuntimeError("MongoDB尚未初始化，请先调用initialize()")
+        return cls._db
+    
+    @classmethod
+    def get_sync_db(cls):
+        """获取同步数据库实例"""
+        if not cls._sync_initialized:
+            cls.initialize_sync()
+        return cls._sync_client[MONGODB_DATABASE]
+    
+    @classmethod
+    async def close(cls):
+        """关闭MongoDB连接"""
+        if cls._client:
+            cls._client.close()
+            await asyncio.sleep(0.1)  # 等待连接关闭
+            cls._initialized = False
+            logger.info("MongoDB异步连接已关闭")
+        
+        if cls._sync_client:
+            cls._sync_client.close()
+            cls._sync_initialized = False
+            logger.info("MongoDB同步连接已关闭")
+
+# 创建全局MongoDB实例
+mongodb = MongoDB()
+
+async def get_mongodb_db() -> AsyncIOMotorDatabase:
+    """获取MongoDB数据库实例（用于依赖注入）"""
+    if not MongoDB._initialized:
+        await MongoDB.initialize()
+    return MongoDB.get_db()
+
+def get_mongodb_sync_db():
+    """获取MongoDB同步数据库实例（用于依赖注入）"""
+    return MongoDB.get_sync_db()