// ImageStore holds immutable images shared by the root, children, and
// subagents. Names are the SHA-256 of the bytes with the decoded format as
// extension. Publication is atomic and does not replace an existing image.
// ImageStore holds immutable images shared by the root, children, and
// subagents. Names are the SHA-256 of the bytes with the decoded format as
// extension. Publication is atomic and does not replace an existing image.