- reaction.rs: query before insert to detect new vs duplicate reactions,
only publish Redis event when a reaction was actually added
- room.rs: delete Redis seq key on room deletion to prevent seq
collision on re-creation
- message.rs: use Redis-atomic next_room_message_seq_internal for
concurrent safety; look up sender display name once for both
mention notifications and response body; add warn log when
should_ai_respond fails instead of silent unwrap_or(false)
- ws_universal.rs: re-check room access permission when re-subscribing
dead streams after error to prevent revoked permissions being bypassed
- RoomChatPanel.tsx: truncate reply preview content to 80 chars
- RoomMessageList.tsx: remove redundant inline style on message row div
