website/vite.config.ts reads the root Cargo.toml at build time and stamps it
into __APP_VERSION__, which the footer and the page chrome render. Pages only
fired on `website/**`, and a release touches Cargo.toml and CHANGELOG.md and
nothing else, so the site never rebuilt for one: the footer kept advertising the
previous version until somebody happened to edit the website for other reasons.
That it currently reads v18.0.0 is luck — a docs commit landed the day after the
release.
Cargo.toml is left out of the pull_request paths on purpose. A dependency bump
changes nothing the site renders, and it is the deploy that needs the trigger.
Michel de Graaf
35f50981ab