* fix(slack): terminalize a progress card detached by a concurrent mention
Rapid mentions in one Slack conversation fire the draft-message boundary
notifier, which calls forceNewMessage and clears the draft stream's message
identity so later output lands below the human message. The already-posted
Working card survives in Slack but becomes unreachable: finalize(), clear(),
and the drop-on-failed-finalize fallback all key on the stream's current
identity, so the card stays at Working forever.
Retain messages the draft stream abandons while un-finalized, expose
dropDetachedMessages(), and drain it from the card's finalize path so final
delivery, error closeout, and turn rotation all terminalize. Also implement
onQueuedFollowupSettled so a queued turn draining after its dispatch already
returned cannot leave a card in Working state. Both cleanups are gated on the
session-card mode: partial/append previews hold streamed assistant text the
human already replied to and must stay visible.
* fix(slack): drain detached cards appended during an in-flight delete
The detached-card drain snapshotted its queue, so a human message routed
synchronously through the conversation boundary during an awaited delete
appended a card the same drain would never remove. The silent-turn closeout
also dropped before its clear(), leaving that window unowned.
Drain until the queue is stable and make the drain the last act on the silent
exit path, so a card detached mid-cleanup still reaches removal.
Peter Steinberger
c58dbaff22