v3接口restful风格，规范化接口；添加mcp服务器；新增log模块

backend/core/config.py

@@ -1,5 +1,9 @@
 from pydantic_settings import BaseSettings, SettingsConfigDict
+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 Settings(BaseSettings):
     """
     系统配置类