refactor: implement reverse proxy for enhanced code commit authorization

Author: wangeguo

.env.example

@@ -10,8 +10,11 @@ DATABASE_URL=postgresql://stackclass:123456@localhost/stackclass
 # Allowed CORS origin.
 ALLOWED_ORIGIN=*
 
+# Git proxy endpoint.
+GIT_PROXY_ENDPOINT=http://git.stackclass.local
+
 # Git server endpoint.
-GIT_SERVER_ENDPOINT=http://git.stackclass.local
+GIT_SERVER_ENDPOINT=http://repo.stackclass.local
 
 # Username for authenticating with the git server.
 GIT_SERVER_USERNAME=stackclass