Inject the Umami tracking script into index.html via a build-only Vite
plugin (apply: 'build'), so it loads on production but never on the dev
server. Website id comes from PUBLIC_UMAMI_WEBSITE_ID with a fallback to
the gethumanai.pl stats id. The SPA serves PL and EN from the same
index.html, so both language versions get the tag.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Oskar Kapala