StaticFiles defaults to check_dir=True, which raises at import time if
frontend/dist/assets is missing on restart — taking down /healthz and
/auth/* along with the frontend. Pass check_dir=False so the mount never
crashes the app, and make the SPA fallback return a clear 503 instead of
an unhandled 500 when index.html is absent.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013PphXq1s43DNRj1uWKGXof
