Custom CI runner image combining cirruslabs/flutter:stable with Node 20
from the official node image, so Gitea Actions runners can execute
JS-based actions (actions/checkout, actions/upload-artifact, etc.) on
Flutter projects.
Registry host is configurable via the vars.REGISTRY_HOST Gitea variable;
weekly cron picks up upstream patch updates without source changes.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
