feat: 完善 Docker 编排文件，添加网络配置和 Nginx 配置

backend/docker-compose.dev.yml

@@ -1,5 +1,9 @@
 version: '3.8'
 
+networks:
+  backend-network:
+    driver: bridge
+
 services:
   # Nginx 网关
   nginx:
@@ -10,6 +14,8 @@ services:
       - ./nginx.conf:/etc/nginx/nginx.conf:ro
     depends_on:
       - gateway
+    networks:
+      - backend-network
 
   # 网关服务
   gateway:
@@ -24,6 +30,8 @@ services:
     depends_on:
       - user-svc
       - redis
+    networks:
+      - backend-network
 
   # 用户服务
   user-svc:
@@ -37,6 +45,8 @@ services:
     command: air -c .air.toml
     depends_on:
       - postgres
+    networks:
+      - backend-network
 
   # 数据库
   postgres:
@@ -50,6 +60,8 @@ services:
     volumes:
       - postgres-data:/var/lib/postgresql/data
       - ./services/user-svc/migrations:/docker-entrypoint-initdb.d
+    networks:
+      - backend-network
 
   # Redis
   redis:
@@ -58,6 +70,8 @@ services:
       - "6379:6379"
     volumes:
       - redis-data:/var/lib/redis/data
+    networks:
+      - backend-network
 
 volumes:
   postgres-data: