Lohnt sich dein eigenes Typeform?

Build me a one-question-at-a-time survey app to replace Typeform, personal scale. Requirements:

- Node + Express + better-sqlite3 on my VPS behind Caddy. A form is a YAML file in
  forms/ (types: text, email, select, rating 1-5, yes/no), loaded at request time.
  No visual builder.
- Public page at /s/<slug>: one question on screen, large type, Enter or click to
  advance, up arrow to go back, progress bar, thank-you screen. Vanilla JS, no
  framework, works on a phone.
- Simple branching: a question may declare next: per answer. One level deep, do not
  build a logic engine.
- Responses saved on completion to SQLite with timestamp and form version.
- CSV export at /admin/<slug>.csv behind an ADMIN_TOKEN from .env; optional webhook
  POST per completed response, URL set in the form's YAML.
- Honeypot field and a per-IP rate limit for spam, nothing fancier.
- No accounts, no telemetry; respondent data stays in my SQLite file.
- Out of scope: a drag-and-drop editor, payments, analytics dashboards, and
  partial-response capture. Adding a form means dropping a YAML file on the server.
- README: Caddy snippet and the YAML form format with one full example.