[xtmhub] Prevent user from seeing 'register'/'unregister' buttons in the demo instance

[jbanety]

Description

On the demo platform (demo.openaev.io), the "Register in XTM Hub" and "Unregister from XTM Hub" buttons are displayed and clickable. These actions should not be available in demo mode, as registration/unregistration should not be triggered from the demo environment.

Environment

1. OS (where OpenAEV server runs): Any
2. OpenAEV version: Current
3. OpenAEV client: Frontend
4. Other environment details: Demo platform (https://demo.openaev.io)

Reproducible Steps

1. Go to https://demo.openaev.io
2. Navigate to Settings > Experience > XTM Hub tab
3. Observe the "Register in XTM Hub" (or "Unregister from XTM Hub" if already registered) button is visible and clickable

Expected Output

The Register/Unregister XTM Hub buttons should not be displayed when the platform is running in demo mode.

Actual Output

The buttons are displayed and functional, allowing users to trigger registration or unregistration from the demo platform.

Additional information

Related to FiligranHQ/xtm-hub#1784