Run the pinned renovate/renovate image on the host runner every weekday at
04:17 (plus workflow_dispatch) against the gitea platform, authenticating with
the renovate-bot RENOVATE_TOKEN Actions secret. Minor and patch updates are
grouped and automerged only after CI passes; majors wait for dashboard
approval. Document the bot, secret rotation and the minimumReleaseAge policy in
the error-centre runbook.