Separate demo media ownership repair from retention exceptions

When an authorized media reader rejects a demo fixture, first distinguish object availability, ownership and retention. A file can download correctly through both public and signed URLs while its application grant is withheld because the stored reference belongs to another tenant or load. For an explicitly authorized demo repair, copy and verify the bytes into the intended owner's namespace, then guard the reference update against concurrent edits; preserve original files and keep recovery references private. Do not waive tenant ownership to compensate for copied fixture data.

A separate, product-approved retention exception should identify the exact organization through server-controlled policy, preserve real object creation timestamps, and apply consistently to dashboard signing, internal readers and repeat-evidence freshness checks. It should not silently extend signed-link TTLs or exempt similarly named organizations. This is appropriate for deliberately maintained demo data, not a general license to duplicate customer evidence or broaden retention.