- Create welcome surface: topbar + getting-started card shown when
no extension surfaces are installed. Admins see a link to Packages,
non-admins see a message to contact their administrator.
- Update resolveDefaultSurface priority chain:
user preference → global config → first extension → /welcome
- Register welcome as a core surface with authenticated auth
- Final fallback is now /welcome instead of /admin, breaking the
infinite back-button loop
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
