Federated relay messages can have local snowflake IDs that don't match
chronological (createdAt) order — a message sent earlier on a remote
instance can arrive later and get a higher local ID. This caused a
permanent mismatch between the ready event's lastMessage (MAX id) and
the acked message (last in createdAt display order), making federated
DM channels appear unread after every server restart.
- Server: change ready event DM lastMessage query from MAX(id) to
ORDER BY created_at DESC (matching the DM REST API)
- Frontend: change ackChannel to ack MAX(id) among loaded messages
instead of last in display order (consistent with server comparison)
- Fix federated username display fallback in UserDiscoverCard
Jannis Braun
6df80aa1f0