dashboard: replace agent-tab transient list with build-queue summary banner

The SW4RM tab rendered a per-transient spinner list above the container
list, duplicating the running-step badge already shown on each agent card.
Replace it with a single compact amber banner that appears when the rebuild
queue has active (queued/running) entries — 'build queue — N running / M
queued — view queue →', linking to the full queue on /core.html. Per-agent
detail stays on the cards; the top of the tab just gives the at-a-glance
summary + a jump to the queue. Closes #1817.

docs/web-ui/dashboard.md

@@ -767,6 +767,14 @@ per-agent actions and navigation links. Contents:
 agent is stale. Banner pulses on each broker SSE event
 (`pulseBanner` with a 4s grace timer).
 
+**Build-queue summary banner** — when the rebuild queue has any
+`queued` / `running` entries, a compact amber banner sits above the
+container list: `◐ build queue — N running · M queued — view queue →`
+(the link goes to the C0R3 page's R3BU1LD QU3U3). It replaces the
+old per-transient spinner list; the actual running step for each
+agent is already shown on its card (transient + in-flight-queue
+badges), so the top of the tab only needs the at-a-glance summary.
+
 ### Themed dialogs
 
 All confirmations, prompts, and transient error notices use an

frontend/packages/dashboard/src/dashboard.css

@@ -564,6 +564,31 @@ body.dashboard-shell {
 }
 .port-conflict strong { color: var(--red); }
 
+/* Build-queue summary banner on the SW4RM tab: one compact line
+   when the rebuild queue has active work, with a link to the full queue on
+   the C0R3 page. Amber to match the in-progress / "rebuilding" card tint. */
+.queue-summary {
+  display: flex;
+  align-items: center;
+  gap: 0.4em;
+  flex-wrap: wrap;
+  background: color-mix(in srgb, var(--amber) 8%, transparent);
+  border: 1px solid color-mix(in srgb, var(--amber) 55%, transparent);
+  color: var(--amber);
+  padding: 0.45em 0.8em;
+  margin-bottom: 0.6em;
+  border-radius: 4px;
+}
+.queue-summary strong { color: var(--amber); }
+.queue-summary-link {
+  margin-left: auto;
+  color: var(--amber);
+  text-decoration: none;
+  font-weight: bold;
+  white-space: nowrap;
+}
+.queue-summary-link:hover { text-decoration: underline; }
+
 /* .notif-row / .btn-notif moved to settings.css with the S3TT1NGS
    page. */
 

frontend/packages/dashboard/src/tabs.js

@@ -808,19 +808,26 @@ window.marked = marked;
       ));
     }
 
-    if (transientsState.size) {
+    // Queue-summary banner: when the rebuild queue has active work,
-      const ul = el('ul');
+    // show one compact at-a-glance line + a link to the full queue on the
-      const nowUnix = Math.floor(Date.now() / 1000);
+    // C0R3 page. Replaces the old per-transient spinner list — the actual
-      for (const [name, t] of transientsState) {
+    // running step is already visible per-agent on each card (transient +
-        const secs = Math.max(0, nowUnix - t.since_unix);
+    // in-flight-queue badges), so the top of the tab only needs the summary.
-        ul.append(el('li', {},
+    const activeQueue = rebuildQueueState.filter(
-          el('span', { class: 'glyph spinner' }, '◐'), ' ',
+      (e) => e.state === 'queued' || e.state === 'running',
-          el('span', { class: 'agent' }, name), ' ',
+    );
-          el('span', { class: 'role role-pending' }, t.kind + '…'), ' ',
+    if (activeQueue.length) {
-          el('span', { class: 'meta' }, `nixos-container create + start (${secs}s)`),
+      const running = activeQueue.filter((e) => e.state === 'running').length;
-        ));
+      const queued = activeQueue.length - running;
-      }
+      const parts = [];
-      root.append(ul);
+      if (running) parts.push(`${running} running`);
+      if (queued) parts.push(`${queued} queued`);
+      root.append(el('div', { class: 'queue-summary' },
+        el('span', { class: 'glyph spinner' }, '◐'), ' ',
+        el('strong', {}, 'build queue'), ' — ',
+        parts.join(' · '), ' ',
+        el('a', { class: 'queue-summary-link', href: '/core.html' }, 'view queue →'),
+      ));
     }
 
     if (!containers.length && !transientsState.size) {