- api/google-calendar.js: service account JWT auth + freebusy query
using only Node.js built-in crypto (no new npm deps). In-memory cache:
5-min busy dates, 1-hr OAuth token. Gracefully returns empty busy list
when GOOGLE_CALENDAR_ID / GOOGLE_SERVICE_ACCOUNT_JSON not configured.
- api/server.js: GET /api/availability?year=YYYY&month=MM endpoint
with 5-min Cache-Control; errors return { busy:[], configured:false }
so the UI always works even if Calendar is unavailable.
- src/index.html: replace plain <input type="date"> in step 1 with a
custom month-grid calendar (dpInit/dpRender/dpNav/dpSelectDate).
Hidden #session-date input carries the value for the rest of the wizard.
Past dates and busy dates are visually blocked; month nav pre-fetches.
- tests/booking.spec.js: 4 new calendar UI tests + updated openAndPickDate
helper to click a rendered day cell.
- tests/api.spec.js: 2 new availability endpoint tests.
Setup: set GOOGLE_CALENDAR_ID and GOOGLE_SERVICE_ACCOUNT_JSON in api/.env.
See api/google-calendar.js header for step-by-step instructions.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
