移除 backend .env，暂时关闭 JWT，改为一次性登录

docker-compose.yml

@@ -32,7 +32,7 @@ services:
       context: ./web
       dockerfile: backend/Dockerfile
     container_name: trade-web
-    env_file: ./web/backend/.env
+    # .env 已移除，环境变量直接写在此处
     environment:
       - LISTEN_ADDR=:8080
       - DATABASE_URL=postgres://trade:trade@postgres:5432/futures?sslmode=disable