Panels no longer flicker on every sync poll.updateCard is now a no-op (no write, no card-state publish, no updated_at bump) when no field actually changed — previously every 45s poll reshuffled board order, rewrote "Idle since" labels, and reloaded all panels. Panel loads also enter the loading state only on first mount, so background refreshes update silently instead of blanking to skeletons and unmounting the tour.