- Bucket finished subagents as `done` instead of `attention`; drop
"needs attention" segment from the section header — subagents are
transient and don't carry an unread state worth surfacing.
- Gate the subagents selector on the existing pending-archive query so
optimistic archives survive authoritative agent snapshots that wipe
the local `archivedAt`. Last subagent archived now cleanly hides the
whole track via the existing empty-rows guard.