fix(config): 修复openapi配置项布局问题

- 为openapi配置项添加col(6)布局属性
- 确保配置界面中openapi相关字段正确对齐显示

Author: smthing

plugins/enterprise-plugin/src/main/java/tech/smartboot/mqtt/plugin/EnterprisePlugin.java

@@ -194,7 +194,7 @@ public Schema schema() {
         showMetrics.addEnums(Enum.of("messages_qos2_sent", "发送给客户端的 QoS 2 消息数量"));
         schema.addItem(showMetrics);
 
-        Item openapi = Item.Object("openai", "openai服务配置");
+        Item openapi = Item.Object("openai", "openai服务配置").col(6);
         openapi.addItems(Item.String("url", "OpenAI URL"));
         openapi.addItems(Item.Password("apiKey", "API秘钥").col(6));
         openapi.addItems(Item.String("model", "模型").col(6));