CSS-only font probe PoC

This page uses only HTML and CSS. Open the Network tab or inspect server access logs for requests to /font-probe. A request for font=... means that local font was not found, so the browser tried to fetch the CSS fallback.

Example: if font=lucida-grande is absent from the logs but font=ms-gothic is present, that is consistent with Lucida Grande being available locally and MS Gothic being unavailable locally.