Persist config on failure

When there is an issue in the URL or port or token during setup, all informations are cleared. It would be nice if the y will be kept in the field to adjust and not need to type in again.

<img width="618" height="625" alt="Image" src="https://github.com/user-attachments/assets/d69da7e9-3c3c-4034-86e5-c943c8ee5b74" />
