修复：IoT数据库连接支持mysql-connector-python驱动

腾讯云MySQL需要use_pure+ssl_disabled参数才能认证通过，
当URL使用mysqlconnector驱动时自动添加connect_args

app/models_iot.py

@@ -109,11 +109,16 @@ def get_iot_engine():
         iot_url = settings.iot_database_url
         if not iot_url:
             raise RuntimeError("IOT_DATABASE_URL 未配置，无法连接 IoT 数据库")
+        # mysql+mysqlconnector 需要 connect_args 传递认证参数
+        connect_args = {}
+        if "mysqlconnector" in iot_url:
+            connect_args = {"use_pure": True, "ssl_disabled": True}
         _iot_engine = create_engine(
             iot_url,
             echo=False,
             pool_recycle=1800,
             pool_pre_ping=True,
+            connect_args=connect_args,
         )
         logger.info(f"IoT 数据库引擎已创建")
     return _iot_engine