The canonical Bot Chat is hidden from session lists by design, so
profiles.list's last_session never advances when you message a bot there.
PR #88690 moved the roster PREVIEW to preferred_session but left every
activity signal on last_session — a bot you just messaged showed '6d ago',
never pulsed, never badged, and sorted below stale bots.
New botActivitySession(bot) helper returns the fresher of preferred_session
(the pinned Bot Chat, resolved precisely by the backend) and last_session
(newest visible conversation). All four activity sites key off it now:
- row age label (relativeTime)
- active-now pulse dot + activeBots strip
- unread watermark + activity toast preview
- roster recency sort (activityOf)
Older gateways without the preferred_session resolver degrade to
last_session exactly as before. Backend untouched.
Tests: extracted the real helper into the vm harnesses (no stub drift),
5 new behavior tests; sabotage-verified they fail against the old code.
Teknium
010c9925e3