chore(compose): change frontend port to 7888

docker-compose.yml

@@ -23,7 +23,7 @@ services:
       # Next.js 服务端反代用（可选），仅在你把 NEXT_PUBLIC_API_BASE 设为 /api 时需要
       - BACKEND_INTERNAL_URL=http://backend:8080
     ports:
-      - "3000:3000"
+      - "7888:3000"
     depends_on:
       - backend
     restart: unless-stopped