Separate retry-evidence reads from retry mutation authority

Persisting original and replacement evidence does not guarantee a usable audit experience. Expose a discoverable original-versus-replacement comparison on the canonical history surface, and authorize that read independently from permission to request another retry.

Keep organization and team scope, evidence redaction, and multiple-retry history intact. Privileged inspection and retry mutation may have different authority; a client that skips the history request can hide persisted evidence even when the endpoint and storage are correct.