npm ci wants a lockfile, so an agent starting from an empty directory cannot use
the example configuration until it has written a whole npm project. This one
runs a server.js on node's own http module with no install step at all, which
makes the shortest loop that exercises all three servers: write a file, start it,
open it in the browser.
It reads the port from PORT as well as from the argument. An agent writing a
server from scratch reaches for process.env.PORT far more readily than for argv,
and a preview listening on the wrong port fails its health check with nothing in
the log to explain why.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Lucio Lelii