update for pc server

asf-cloud-server/testarena/DEPLOYMENT.md

@@ -119,9 +119,22 @@ Ensure your Nginx is configured to serve the app.
 
 ## Troubleshooting
 
+- **npm: command not found**:
+  You need to install Node.js and npm on your server.
+  ```bash
+  sudo apt update
+  sudo apt install nodejs npm
+  ```
+
+- **Permission denied (Docker)**:
+  The script tries to handle this by using `sudo`. If running manually, use `sudo docker-compose ...` or add your user to the docker group:
+  ```bash
+  sudo usermod -aG docker $USER
+  newgrp docker
+  ```
+
 - **Backend not starting?**
-  Check logs: `docker-compose logs -f backend`
+  Check logs: `sudo docker-compose logs -f backend`
+
 - **Frontend 404s?**
   Ensure `try_files $uri $uri/ /index.html;` is present in Nginx config.
-- **WebSocket connection failed?**
-  Ensure the `/ws/` location block has the `Upgrade` headers.