One reserved corner of the shell, one blob per running BACKGROUND
process — session sub-agents (research/demo/visual) and global
extraction runs. Teaching turns are deliberately NOT here: the dock
exists to surface what the learner can't otherwise see; a running
teaching turn is already fully visible where it happens (user decision).
- Data: ONE poll of GET /api/activity (jobs across ALL chats,
title-joined, oldest-first + extraction runs), folded client-side
with core/prices.ts (jobCost). Adaptive interval — 2.5s while
anything runs, 10s idle, 4× slower on hidden tabs; a failed fetch
keeps the last feed (no flicker to empty on a blip).
- Per blob: kind icon, elapsed (ticking), cost, activity line, and an
explicit END on the blob's face. Click → detail popover (context
line, model, steps, open-session link). The context line is the LAST
model call's tokens vs the model's limit (JobUsage.lastStep — pending
agents-stream contract; "—" until it populates), NEVER a cumulative
sum. Absent data renders "—", never zero (the doctrine).
- Header: total running cost (sum of priced blobs, "—" when nothing
is priced). Narrow viewports collapse to a count badge → drawer.
- END posts to /api/activity/abort {kind, id} — the backend is being
composed by master over the streams' mechanisms; until it exists a
click locks the button and the popover says "Abort not available
yet" (never a dead control).
- Idle renders NOTHING. Mounted once in the root layout; every view
gets it for free.
toBlobs / formatElapsed / formatUsd / formatTokens are pure + tested;
SSR render tests pin blobs, the "—" doctrine, the face END, and the
priced total.