fix(gateway): 默认监听端口改为 8084 以支持非 root 运行

- Dockerfile 及 main.rs 默认 bind 从 0.0.0.0:80 改为 0.0.0.0:8084
- docker-compose 以 UID:GID 非 root 用户启动 app 容器
- compose 端口映射与容器内监听端口保持一致，通过 AETHER_GATEWAY_BIND 注入

docker-compose.build.yml

@@ -50,13 +50,14 @@ services:
       DATABASE_URL: postgresql://postgres:${DB_PASSWORD}@postgres:5432/aether
       REDIS_URL: redis://:${REDIS_PASSWORD}@redis:6379/0
       TZ: Asia/Shanghai
+      AETHER_GATEWAY_BIND: 0.0.0.0:${APP_PORT:-8084}
     depends_on:
       postgres:
         condition: service_healthy
       redis:
         condition: service_healthy
     ports:
-      - "${APP_PORT:-8084}:80"
+      - "${APP_PORT:-8084}:${APP_PORT:-8084}"
     volumes:
       - ./logs:/app/logs
     restart: unless-stopped