v3接口restful风格，规范化接口；添加mcp服务器；新增log模块

backend/core/database.py

@@ -1,7 +1,11 @@
 from sqlalchemy import create_engine, MetaData, Table
 from pgvector.sqlalchemy import Vector
 from .config import settings
+import logging
 
+# 获取当前模块的专用 Logger
+# __name__ 会自动识别为 "backend.services.crawler_service" 这样的路径
+logger = logging.getLogger(__name__)
 class Database:
     """
     数据库单例类
@@ -30,9 +34,9 @@ class Database:
             self.tasks = Table('crawl_tasks', self.metadata, autoload_with=self.engine)
             self.queue = Table('crawl_queue', self.metadata, autoload_with=self.engine)
             self.chunks = Table('knowledge_chunks', self.metadata, autoload_with=self.engine)
-            print("[INFO] Database tables reflected successfully.")
+            logger.info("Database tables reflected successfully.")
         except Exception as e:
-            print(f"[ERROR] Failed to reflect tables: {e}")
+            logger.error(f"Failed to reflect tables: {e}")
 
 # 全局数据库实例
 db = Database()