Freeze Proves What You Saw
A frozen package is valuable because later readers can compare evidence against the same premises. The brief identifies the instructions; the manifest identifies attachments; content digests identify the exact bytes. Together they answer the review question that memory cannot: what did the executor actually receive?
A hash is narrow evidence. It proves equality of bytes when recomputed under the same algorithm. It does not prove the attachment was correct, safe, or authorized. Those are separate checks. Overclaiming a digest turns a useful instrument into security theater.
The freeze also protects the author. If a source packet is corrected after take, the original session should not be blamed for failing to use information it never had. A superseding delegation can carry the corrected bytes while the first record remains an honest account.
Review tools should display both human names and digests. Names make the package understandable; digests make substitution detectable. The landing record can cite the frozen package identity without copying private content into a public or long-lived log.
Recompute at Review
When a reviewer opens an attachment, recompute its digest and compare it to the frozen manifest before judging content. A mismatch is a package-integrity blocker, not a content finding.
Then preserve the distinction in reporting: “bytes match the frozen package” and “the document satisfies the task” are two claims with two instruments. Passing the first is necessary for fair review and insufficient for acceptance.