Description
Add the latest commit ID (scoped to the website/ folder) to the homepage footer, so we can determine which commit was used to build the currently deployed site.

The commit hash is displayed as a clickable link pointing to the commit on GitHub, placed below the Netlify icon and text in the footer's right section.

Implementation:

• Inject HUGO_PARAMS_COMMITFULL and HUGO_PARAMS_COMMITSHORT env vars via git log -1 --format=%H -- . at build time in npm run build/dev scripts
• Footer template reads site.Params.commitfull / site.Params.commitshort and renders a link using site.docsRepo config for the base URL
• Graceful fallback: nothing shown if env vars not set

Done Criteria

• Commit hash visible in homepage footer after npm run build
• Commit hash links to correct GitHub commit URL
• Works for npm run dev during local development
• No visible change when env vars are absent (graceful fallback)