after reverting the 3-column attempt (74ba8a6), keep the
single-column layout but put related sections adjacent:
swarm: containers → kept-state → meta-inputs
decisions: questions → approvals
messages: operator-inbox → message-flow + compose
this is a free improvement — the operator scrolls through one
logical group at a time instead of bouncing between swarm /
decisions / messages mid-page. follow-up improvements
(collapsing rarely-active sections, multi-column at wide
viewports done less aggressively) captured in TODO under
'Dashboard layout overhaul'.