The debug tab was defined in the tabs array and had all the state and
functions set up, but was missing the actual JSX rendering block.
This caused the debug dumps to not be displayed in the admin interface.
- Add User model with authentication
- Create JWT-based auth service
- Add login page with admin/admin default credentials
- Create admin panel with user management, settings, and site configuration
- Move settings to admin section (admin only)
- Change search page from multi-site checkboxes to single site selector
- Add logout functionality to layout
- Protect routes with authentication