chore: harden build and deployment workflow

docker-compose.yml

@@ -7,8 +7,6 @@
 #   3. 访问: http://localhost (或配置的域名)
 # ============================================
 
-version: '3.8'
-
 services:
   # ============================================
   # 后端服务
@@ -32,6 +30,8 @@ services:
       # 数据持久化
       - ./backend/data:/app/data
       - ./backend/storage:/app/storage
+      # 桌面安装包由管理端发布，前后端共享此目录
+      - ./frontend/downloads:/frontend/downloads
     networks:
       - wanwanyun-network
     healthcheck:
@@ -45,15 +45,17 @@ services:
   # Nginx 前端服务
   # ============================================
   nginx:
-    image: nginx:alpine
+    build:
+      context: ./frontend
+      dockerfile: Dockerfile
     container_name: wanwanyun-nginx
     restart: unless-stopped
     ports:
       - "80:80"
       - "443:443"
     volumes:
-      # 前端静态文件
-      - ./frontend:/usr/share/nginx/html:ro
+      # 动态发布的桌面安装包覆盖镜像内初始版本
+      - ./frontend/downloads:/runtime/downloads:ro
       # Nginx 配置
       - ./nginx/nginx.conf:/etc/nginx/conf.d/default.conf:ro
       # SSL 证书（如有）