When the JWT expired, AuthGate redirected window.location to /auth/login
which loaded inside the portal iframe. The portal detected window.self !==
window.top and showed the EmbeddedFallback ("This app isn't available yet")
instead of the login page.
Redirect window.top instead so the portal itself navigates to /login.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>