fix(website): keep the repository star count current #369

User problem

The website shows a committed repository-star snapshot that remains unchanged as people star the project. The call to action can therefore display a visibly stale count until another website deployment.

GitHub reported 147 stars while the published surface still showed 88.

Root cause

The website imports a static repository snapshot and previously had no runtime refresh path.

Acceptance criteria

• The deployed website refreshes repository metadata without a rebuild or redeployment.
• Visitors request a same-origin website endpoint rather than contacting GitHub directly.
• The server caches successful public GitHub responses so page views cannot exhaust the upstream rate limit.
• Serve stale cached data during GitHub timeouts, rate limits, and temporary upstream failures.
• Validate the runtime response and accept only a non-negative integer star count plus a valid update timestamp.
• Keep the bundled snapshot for initial rendering and as a client-side fallback.
• Refresh when the page opens, periodically while it remains open, and when a background tab becomes visible again.
• Runtime refresh failures remain silent and never replace a valid count with an error.
• SSR, prerendering, client hydration, and the production container remain functional.
• Tests cover live refresh, malformed responses, upstream failure, snapshot preservation, and same-origin routing.

Relationships

• Parent: [EPIC] Platform UX, quality, and releases #16
• Introduced with the website download surface in feat(release): add stable platform downloads #349.