The old activity dock (fixed bottom-right, every view) was a cross-session
widget parked inside the session view — the same boundary confusion that
got the plan window moved. The sidebar is the app's cross-session surface,
so the agents section lives at its bottom strip now (user-locked design):
- ALWAYS present: empty means empty — the header ('Background agents',
matching the Sessions label language) sits alone; nothing hides and
nothing decorates (the total-cost span only renders when populated).
- Populates and grows when processes run: same blobs (sub-agents +
extraction runs, one poll, inferred cost, elapsed heartbeat), capped by
max-h-[40dvh] + internal scroll so a pile never crowds the session list.
- Per-blob END button (unchanged abort contract); the detail popover
becomes an INLINE expansion — the section scrolls, a floating popover
would clip at its bounds.
- Sidebar-native skin: border-t separator matching the sidebar's edge,
session-row hover language, no floating-card chrome.
- Sidebar closed = the learner opted out; no ambient signal for now
(user decision — invisibility until a clearer observability story).
- Narrow-mode count badge/drawer machinery retired with the dock.
app/layout.tsx: ActivityDock mount removed, ActivityProvider stays (the
sidebar consumes the context). Live-verified: populated rows with inline
detail + session link, abort makes the row vanish, idle renders the
header alone, closed sidebar hides the section with nothing floating.
Gates: typecheck, lint, 423/423 tests.
amosblomqvist
bbee72f354