release(v1.7.38-alpha): onboarding auto-heal + silent returning logins + app-store trim

- auth.rs now infers onboarding-complete from setup_complete + password_hash so
  nodes stop bouncing users through the intro wizard after browser clear / update
  / reboot; the flag self-heals to disk on next check
- frontend: "backend uncertain" no longer defaults to /onboarding/intro —
  useOnboarding returns null + callers poll / retry instead of flashing the wizard
- login sounds (synthwave, welcome voice, pop, whoosh, oomph) gated by
  isFirstInstallPhase(); typing sounds unaffected
- removed FIPS app, Nostr Relay, Nostr VPN, Routstr, Penpot from catalog,
  frontend config, Rust AppMetadata + install dispatch + install_penpot_stack;
  docker/fips-ui + docker/nostr-vpn-ui + apps/penpot dirs and 5 icons deleted;
  15 image versions deleted from tx1138, .168, gitea-local registries (.160
  Gitea was 502 at release time — follow-up)
- AIUI baked into frontend release tarball via demo/aiui/; deploy-to-target
  falls back to demo/aiui/ when the AIUI sibling checkout is missing
- prebuild hook syncs app-catalog/catalog.json → public/catalog.json so the
  two copies can no longer drift (was the source of the "apps still visible"
  bug — public/ had stale data)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

docker/fips-ui/Dockerfile

@@ -1,10 +0,0 @@
-FROM git.tx1138.com/lfg2025/nginx:1.27.4-alpine
-COPY index.html /usr/share/nginx/html/
-COPY nginx.conf /etc/nginx/conf.d/default.conf
-RUN sed -i 's/^user  nginx;/user  root;/' /etc/nginx/nginx.conf && \
-    mkdir -p /var/cache/nginx/client_temp /var/cache/nginx/proxy_temp \
-             /var/cache/nginx/fastcgi_temp /var/cache/nginx/uwsgi_temp \
-             /var/cache/nginx/scgi_temp
-EXPOSE 8202
-ENTRYPOINT []
-CMD ["nginx", "-g", "daemon off;"]