Lohnt sich dein eigenes SavvyCal?

Build me a solo booking page to replace SavvyCal: one person, one calendar, a few link
types. Requirements:

- Node + Express + better-sqlite3 on my VPS behind HTTPS; server-rendered pages, Luxon
  for timezone math.
- Link types in links.json: slug, title, duration, buffer, allowed hours (e.g. /intro,
  30-min slots, 15-min buffer, weekdays 10:00-16:00 my time).
- Availability from Google Calendar free/busy (googleapis, OAuth creds in .env); show
  open slots for the next 14 days in the visitor's detected timezone with a timezone
  switcher.
- Booking form: name + email + note. On submit, create the event on my calendar with the
  guest as attendee so Google sends the invite, and store the booking in SQLite.
- Re-check free/busy at submit time, not just render time, so two guests cannot grab the
  same slot.
- Confirmation email to guest and me via Resend or SMTP (creds in .env), including a
  cancel link that deletes the event.
- No accounts, no telemetry beyond my own server logs.
- Out of scope: team links, routing, payments, and reminder sequences. One calendar,
  mine.
- README: the Google Cloud console OAuth steps (budget an hour, it is the worst part)
  and the DNS/HTTPS notes.