* chore(workflows): complete migration to Blacksmith cloud runners
Migrate remaining workflows from self-hosted axecap runners to Blacksmith:
- docker.yml: publish job
- release.yml: publish job
- security.yml: audit and deny jobs (conditional on push events)
This completes the transition away from self-hosted infrastructure.
Axecap runner registrations (IDs 21, 22) have been removed.
All workflows now use blacksmith-2vcpu-ubuntu-2404 label for consistency.
* Merge branch 'main' into selfhost-blacksmith