v1.5.3 - default base images via mirror.gcr.io Fixes a runner-side reliability issue: the storr runner is unauthenticated to docker.io and tag pipelines that fan out across multiple Go template jobs hit the per-IP unauthenticated pull cap (toomanyrequests). All Go templates default to mirror.gcr.io/library/ golang now; go-sbom + slsa-attest default to mirror.gcr.io/library/ alpine. Both expose 'image' as an input for consumers to override. API-compatible patch release. Consumers that pinned an image input keep their pinned image.