fix(config): Correct three-node HA orchestration and Nacos config loading

backend/docker-compose-node-03.yml

@@ -16,9 +16,6 @@ services:
       - "3306:3306"
     environment:
       MYSQL_ROOT_PASSWORD: ${MYSQL_ROOT_PASSWORD:-root123456}
-      MYSQL_DATABASE: ${MYSQL_DATABASE:-video_platform}
-      MYSQL_USER: ${MYSQL_USER:-video}
-      MYSQL_PASSWORD: ${MYSQL_PASSWORD:-video123}
     volumes:
       - mysql_data:/var/lib/mysql
       # - ./sql:/docker-entrypoint-initdb.d  # 从节点不需要初始化脚本，数据从主库同步
@@ -87,7 +84,7 @@ services:
       - NACOS_SERVER_IP=${HOST_IP:-192.168.1.103}
       - NACOS_APPLICATION_PORT=8848
       - SPRING_DATASOURCE_PLATFORM=mysql
-      - MYSQL_SERVICE_HOST=mysql
+      - MYSQL_SERVICE_HOST=192.168.1.101
       - MYSQL_SERVICE_PORT=3306
       - MYSQL_SERVICE_DB_NAME=nacos_config
       - MYSQL_SERVICE_USER=root
@@ -211,7 +208,7 @@ services:
     container_name: node-exporter
     restart: always
     ports:
-      - "9100:9100"
+      - "19100:9100"
     command:
       - --path.procfs=/host/proc
       - --path.sysfs=/host/sys