Add thv logs additional flags to troubleshooting docs

Document --follow and --proxy flags for the thv logs command to help
users debug authentication issues more effectively:
- --follow: Follow logs in real-time (like tail -f)
- --proxy: View proxy logs instead of container logs

Author: jhrozek

docs/toolhive/_partials/_auth-troubleshooting.mdx

@@ -8,7 +8,14 @@ If clients can't authenticate:
 4. Check the server logs for specific authentication errors:
 
    ```bash
+   # View logs
    thv logs <server-name>
+
+   # Follow logs in real-time (like tail -f)
+   thv logs <server-name> --follow
+
+   # View proxy logs instead of container logs
+   thv logs <server-name> --proxy
    ```
 
 ### Authorization issues