dashboard: split queued vs running rebuild visual (#769)

Container row's pending highlight fired for both queued + running
rebuild-queue entries, so a long queue painted half the SW4RM tab
amber. Mara on #769: don't highlight while queued, show running as
spinner on agent icon.

- tabs.js: derive opRunning (transient OR op.state === 'running')
  separately from pending; add a pending-running row class.
  Operator-initiated transients still count as running so the
  rebuild-now-clicked → backend-picks-it-up window stays visually
  consistent.
- dashboard.css: move the amber border + tint from .pending to
  .pending-running (queued rows now keep their normal look, with
  the badge text still saying "rebuild queued"). Add a 1s linear
  rotating amber arc as .pending-running > .container-icon::after,
  with overflow:visible so the ring sits just outside the icon and
  composes with the mauve selected ring.
- docs/web-ui.md::Container row: describe the queued vs running
  split in prose. Drop the orphaned (#398) cookie while I'm at it
  — small #712 freebie.

frontend/packages/dashboard/src/tabs.js

@@ -497,10 +497,19 @@ window.marked = marked;
               : (op.kind === 'meta_update' ? 'meta-update queued'
                   : op.kind === 'destroy'  ? 'destroy queued'
                   : 'rebuild queued')));
+      // Split the visual into queued vs running (#769): queued ops get
+      // no row highlight — the badge text alone says "wait, queued" —
+      // while running ops keep the amber row tint + add a rotating
+      // amber ring on the agent icon. Operator-initiated transients
+      // always count as running (the op is already in flight even if
+      // the queue worker hasn't picked it up yet).
+      const opRunning = transientKind != null
+        || (op != null && op.state === 'running');
       const selected = selectionState.has(c.name);
       const li = el('li', {
         class: 'container-row'
           + (pending ? ' pending' : '')
+          + (opRunning ? ' pending-running' : '')
           + (selected ? ' selected' : ''),
       });
       // Topology: depth contributes left-padding; the glyph string in