ReadonlyfailureReadonlynotesReadonlyprojectionDigest over the projected history at the cutoff, including its provenance.
ReadonlyrequestNull exactly when failure is set.
ReadonlysourceOrdered ids of every row the request was assembled from.
Facts that do not stop assembly but should not go unmentioned — chiefly a blob whose content no longer hashes to its row's
payload_sha256. Assembly continues so the caller still gets bytes to compare, and the note says where to look when that comparison fails.