update nginx

Change-Id: Ia5695f05d68dcae340c97a9cdd923ce5b56455d7
diff --git a/nginx.conf b/nginx.conf
index 8673316..90e9a4c 100644
--- a/nginx.conf
+++ b/nginx.conf
@@ -1,7 +1,3 @@
-upstream backend {
-    server backend:5004;  # 保持不变(Docker Compose中服务名即容器间通信域名)
-}
-
 server {
     listen 3004;  # 修改为Docker Compose中映射的前端端口(与docker-compose.yml保持一致)
 
@@ -16,7 +12,7 @@
 
     # 反向代理API请求到后端
     location /api/ {
-        proxy_pass http://backend/;  # 代理路径与后端API前缀匹配
+        proxy_pass http://thunderhub-backend:5004;  # 代理路径与后端API前缀匹配
         proxy_set_header Host $host;
         proxy_set_header X-Real-IP $remote_addr;
         proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;