Root cause, confirmed live against Postgres and reproduced end-to-end
through two real WebSocket connections: ws/chat.py shares one AsyncSession
for a whole connection's lifetime. A read-only action (e.g. a "join"
frame's membership check) can leave a transaction open with nothing to
commit it until the next write. Postgres's now()/CURRENT_TIMESTAMP
returns that transaction's *start* time in that case, not the actual
statement's -- so a reply sent after any idle/reading period got
timestamped to when the idle period started, sorting it before messages
that were genuinely sent earlier. This is independent of the two earlier
#45 fixes (missing ORDER BY tiebreakers, a stale-response race on
reload) -- both were real bugs, but this was the actual mechanism behind
"my message appears before theirs even though theirs was sent first."
Switched Message.created_at and MessageReaction.created_at from
func.now() to func.clock_timestamp(), which always reflects the actual
moment of execution regardless of how long the transaction has been
open. Migration is a plain column-default change -- no table rewrite, no
lock risk, round-trips cleanly.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Composer gains an emoji picker (static curated unicode list, insert at
cursor position) and messages gain Slack/Mattermost-style reactions:
react with any emoji, toggle off by reacting again, see who reacted via
a tooltip on each pill.
Backend: MessageReaction model (unique on message_id+user_id+emoji backs
toggle semantics), WS "reaction" envelope broadcasts the full recomputed
reaction list per message (same approach as message edits), REST message
list embeds reactions so a reload doesn't lose state that only arrived
over WS.
Frontend: shared EmojiPicker component (anchored popover, Escape/outside-
click dismiss via new useEscapeKey hook) used by both the composer and a
new hover-revealed reaction trigger on each message row.