registerSW.js was 404ing in the browser — the PWA plugin was a leftover
from the original port and this is an internal hotel app with no PWA requirement.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Python FastAPI ML backend kept intact; auth replaced with central hnf_session cookie verification. Frontend rebuilt on React 18 + TS + Vite with stack design system, Plotly charts retained. Shared Postgres via DATABASE_URL; schema applied on startup.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>