- Add `registry` field to `ImageRef` (default `"docker.io"`)
- Populate `registry` from `_detect_registry()` in `iter_role_images()`
- `GHCRProvider.image_base()` and `GiteaProvider.image_base()` now produce
`{prefix}/{registry}/{name}` paths (e.g. `mirror/docker.io/nextcloud`,
`mirror/quay.io/keycloak/keycloak`) instead of flattening slashes to dashes
- Fix `mirror()` in both providers: use `docker://{image.source}` directly
instead of always prepending `docker://docker.io/`, which broke quay.io/ghcr.io images
- Update tests to reflect new naming convention and add quay.io test case
- Add missing __init__.py files in test subdirectories
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>