chore: 生产部署适配 — nginx.conf 精简 + .gitignore 更新

- nginx.conf: 移除 /api/ 代理(改由 OpenResty 边缘路由)，仅保留 SPA fallback
- .gitignore: 排除所有 .env.* (保留 .env.example)，防止 .env.production 误提交

Co-Authored-By: Claude <noreply@anthropic.com>

.gitignore

@@ -195,6 +195,8 @@ Thumbs.db
 
 # Env
 .env
+.env.*
+!.env.example
 
 # Deployment docs (contain credentials, not for git)
 *部署交接文档.md

frontend/nginx.conf

@@ -5,22 +5,13 @@ server {
     root /usr/share/nginx/html;
     index index.html;
 
-    # Vue app
+    # SPA fallback
     location / {
         try_files $uri $uri/ /index.html;
     }
 
-    # API proxy
-    location /api/ {
-        proxy_pass http://backend:8000;
-        proxy_set_header Host $host;
-        proxy_set_header X-Real-IP $remote_addr;
-        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
-        proxy_set_header X-Forwarded-Proto $scheme;
-    }
-
+    # Health check
     location /health {
-        proxy_pass http://backend:8000;
-        proxy_set_header Host $host;
+        return 200 "ok";
     }
 }