The thread panel rendered an "Audit" feed — "Chat message sent", "Task
run completed", "Approval requested" rows with monospace timestamps —
a server log sitting inside a conversation. Attachments showed an eight-
character SHA-256 fragment next to the file type. Neither belongs in a
surface a non-technical operator reads as people talking.
Remove the audit replay from the chat thread (and its now-dead
replayEventsForThread/auditPayload plumbing) and drop the checksum from
the attachment card. The audit trail itself is unchanged — it is still
recorded and still shown on the task activity tab. The e2e thread check
now asserts the reply box, not the log.