feat: backend env config upgrade - multi-env (dev/prod), DB_* support, Docker compatible

Co-authored-by: Cursor <cursoragent@cursor.com>

deploy/docker-compose.prod.yml

@@ -61,8 +61,13 @@ services:
     ports:
       - "80:80"
       - "443:443"
-    volumes:
-      - ./nginx.conf:/etc/nginx/conf.d/default.conf:ro
+    # 注意：镜像构建时已经包含了配置，无需挂载
+    # 如果需要覆盖配置，取消下面的注释并确保 nginx.conf 路径正确
+    # volumes:
+    #   - ./nginx.conf:/etc/nginx/conf.d/default.conf:ro
+    environment:
+      - NGINX_HOST=_
+      - NGINX_PORT=80
     depends_on:
       - backend
       - admin