- Fix useElapsedTimer to use completedAt instead of Date.now() for
finished runs, preventing wildly inaccurate durations (e.g. 9802m)
when reopening old sessions
- Extract formatElapsedMs as a shared pure formatter; reuse in
SubagentActivityCard
- Standardize icon column alignment across all activity row types
using consistent w-4 + h-[18px] icon containers
- Redesign collapsed header: status dot with pulse animation, bolder
status label, tabular-nums on elapsed time, cleaner hierarchy
- Polish expanded stream: timeline spine connecting activity items,
more prominent intent dividers with pill-style background,
tightened vertical rhythm
- Add unit tests for formatElapsedMs
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
