Can I vibecode PostHog?

Build me a self-hosted web analytics box to replace PostHog. Requirements:

- One Node 22 + Express process with better-sqlite3, serving the collector and the
  dashboard on port 8787. No frontend framework, no build step, no Docker.
- A tracker.js I paste on my sites: pageviews on load and history change, plus
  window.track('signup', { plan: 'pro' }), POSTed to /e on my own domain so
  collection stays first-party.
- One SQLite events table: site, event, path, referrer, UTM fields, country from the
  proxy header, device class, and a JSON properties blob.
- Count visitors by a daily-rotating salted hash of IP plus user agent, salt in .env.
  No cookie, never the raw IP. That is the whole privacy design, keep it.
- Dashboard at / with a date range picker: visitors and pageviews by day, top pages,
  referrers, countries, any event split by one property, and a three-step funnel.
- Nightly rollup into a daily-summary table, raw events pruned past the retention
  window in .env, /export.csv for the raw rows.
- Basic auth on the dashboard, collector open. No accounts, no telemetry, my box
  holds the only copy.
- Out of scope: session replay, feature flags, and stitching one person across
  devices. Do not build a plugin system or a warehouse connector.
- README: the snippet to paste, where the SQLite file lives, and how to back it up.