Should you build your own Teachable?

Build me a single-course sales site to replace Teachable, for one course of mine. Requirements:

- Node + Express + better-sqlite3 on my VPS behind Caddy. Course content is Markdown
  in content/: one folder per module, one file per lesson, front matter points at an
  optional video file.
- Public landing page: course outline, price, and a Buy button that goes to Stripe
  Checkout (keys in .env). The Stripe webhook marks the buyer's email as enrolled.
- Student login by magic link: enter email, receive a signed login link via SMTP
  creds in .env. No passwords, no OAuth.
- Lesson pages are gated by enrollment; videos are MP4s served through the app with
  short-lived signed URLs so direct links expire.
- Progress: a mark-complete button per lesson and a progress bar per module, stored
  per student in SQLite.
- Receipts come from Stripe; do not build invoicing or tax logic (turn on Stripe Tax
  if needed).
- Out of scope: multiple courses, affiliates, certificates, upsells, coupons, and
  mobile apps. This sells and delivers one course.
- README: Stripe webhook setup, Caddy snippet, where videos live on disk, and an
  honest note that a VPS handles a small audience fine but a big launch needs real
  video hosting like Bunny.net.