Adds a 'tasks' header pill (hidden at zero, like inbox/loose-ends) that
opens a side-panel flyout listing the agent's in-flight bash tasks from
GET /api/bash-tasks. Each row shows status (running/queued), task id,
elapsed time, and a truncated single-line command preview. Polled on the
same /api/state cycle as loose-ends (tasks complete async between turns, so
the count stays live); clicking the pill opens the flyout. Snapshot-only
v1 — SSE live-push is a possible follow-up.
4ce919a19f