Follow the gate and its status

The existing GitHub workflow reports main-push gate outcomes to the Project's private Slack channel. The Forgejo migration must prove that the same gate and notification paths work before switching the Project.

The required notification flow includes failures to read navigator.yaml, failed checks, and recovery. It must resolve the channel from Navigator's trusted repository binding so a broken manifest cannot silence the alert. These are cutover requirements, not a claim that Forgejo notifications are already installed.

Document YAML points to Navigator-managed objects. Keep legal-document bytes in that object store rather than adding them to Git or LFS. Gate success is the outcome to inspect.