Adds a check-changes job to website.yml that queries the Forgejo API for
the last successful website.yml run, compares its head_sha to HEAD, and
diffs for website-relevant paths before deploying. Eliminates ~23 wasteful
hourly rebuilds per day when no website content has changed. Push and
workflow_dispatch triggers are unaffected — they always deploy.
Closes#494
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>