* feat(deploy): add scanner service to release deployment
- Add skill-scanner service to compose.release.yml (enabled by default)
- Add scanner image to CI publish-images workflow matrix
- Add --scanner-image and --no-scanner flags to runtime.sh
- Add scanner config to .env.release.example
* fix(docker): add skillhub-notification module to server Dockerfile
* fix(deploy): set scanner mode to upload for container deployment
* fix(deploy): use env override instead of persisting scanner disabled state
- Change workflow trigger from push events to release published events
- Remove automatic builds on main branch merges
- Keep manual workflow_dispatch option for flexibility
