dashboard: the build pages are tabs of the dashboard

The build lifecycle used to be its own page with three sub-tabs. They are
now dashboard tabs (rebuild, meta, buildlogs) beside SW4RM and
P3RM1SS10NS: builds.js is a module tabs.js imports, so the dashboard's one
tab strip, /api/state snapshot and event stream (plus the meta_inputs_changed
and meta_update_running kinds) serve them, and the page, its bundle entry,
stylesheet and home tile are gone. The SW4RM banner's "view queue" link
points at the #rebuild tab, and the rebuild tab carries a count pill of the
rebuilds in flight.

An empty tab-count pill drew a "0": its display beat the UA [hidden] rule.

frontend/packages/dashboard/src/tabs.js

@@ -34,6 +34,15 @@ import {
   renderContainers,
   renderSelectionBar,
 } from "./swarm.js";
+import {
+  initBuilds,
+  onBuildsTabShown,
+  onMetaInputsChanged,
+  onMetaUpdateRunning,
+  onRebuildQueueChanged,
+  rebuildCount,
+  syncBuildsFromSnapshot,
+} from "./builds.js";
 
 // mdNode (in common.js) reads `window.marked` for the markdown side
 // panel preview path. Set it here on the dashboard entry so file
@@ -146,6 +155,7 @@ window.marked = marked;
       // initJobqRollup mounts once and is a no-op on later calls; the
       // mount's own effect handles the actual fetch.
       initJobqRollup();
+      syncBuildsFromSnapshot(s);
       renderContainers(s);
       restoreOpenDetails(openDetails);
       // No periodic refresh timer. Phase 6 covers every container
@@ -191,11 +201,15 @@ window.marked = marked;
     transient_cleared: applyTransientCleared,
     container_state_changed: applyContainerStateChanged,
     container_removed: applyContainerRemoved,
-    // rebuild_queue_changed: refreshes the SW4RM queue-summary banner
-    // (see swarm.js) — a payload-less push trigger, same treatment
-    // /builds.html gives it for its JobqGraph mount handle's .refresh()
-    // (its own separate subscription).
-    rebuild_queue_changed: applyRebuildQueueChanged,
+    // rebuild_queue_changed: a payload-less push trigger. Refreshes the
+    // SW4RM queue-summary banner (see swarm.js) and the R3BU1LD QU3U3
+    // tab's JobqGraph (see builds.js).
+    rebuild_queue_changed: () => {
+      applyRebuildQueueChanged();
+      onRebuildQueueChanged();
+    },
+    meta_inputs_changed: onMetaInputsChanged,
+    meta_update_running: onMetaUpdateRunning,
     capabilities_changed: applyCapabilitiesChanged,
     tool_groups_changed: applyToolGroupsChanged,
   };
@@ -208,11 +222,12 @@ window.marked = marked;
     // fallback when SharedWorker isn't supported.
     //
     // kinds= matches MUTATION_HANDLERS verbatim, so the stream carries
-    // only the 7 wire kinds this page acts on.
+    // only the 9 wire kinds this page acts on.
     const es = openStream(
       "/api/dashboard/stream?kinds=" +
         "transient_set,transient_cleared," +
         "container_state_changed,container_removed,rebuild_queue_changed," +
+        "meta_inputs_changed,meta_update_running," +
         "capabilities_changed,tool_groups_changed",
     );
     es.onmessage = (e) => {
@@ -245,8 +260,8 @@ window.marked = marked;
   })();
 
   // ─── tab routing ───────────────────────────────────────────────────────
-  // Hash-based: `#swarm` / `#system` / `#permissions` activate the
-  // matching pane on the dashboard. Empty
+  // Hash-based: `#swarm` / `#rebuild` / `#meta` / `#buildlogs` /
+  // `#permissions` activate the matching pane on the dashboard. Empty
   // hash defaults to SW4RM. FL0W and ST4TS are NOT tabs —
   // they're separate pages (`/flow.html`, `/stats.html`) reached from
   // the H0M3 hub. Tab routing only
@@ -272,6 +287,7 @@ window.marked = marked;
       fetchAndRenderCapabilities();
       fetchAndRenderToolGroups();
     }
+    onBuildsTabShown(target);
   }
 
   // Wire the shared tab strip now that activateTab + the lazy-load fns it
@@ -279,6 +295,9 @@ window.marked = marked;
   // (default SW4RM), toggles the active tab/pane + aria-selected, and
   // fires activateTab for the per-tab side-effects on every change.
   createTabStrip($("tabbar"), { defaultId: "swarm", onShow: activateTab });
+  // The rebuild queue mounts now, not on first show, so its tab's count pill
+  // is live from the start.
+  initBuilds();
 
   // Tab count pills — pure derived data from the existing state
   // stores so SSE-driven updates flow through without extra plumbing.
@@ -302,6 +321,8 @@ window.marked = marked;
       if (c.needs_update) swarm++;
     }
     setTabCount("swarm", swarm);
+    // R3BU1LD QU3U3 — rebuilds in flight.
+    setTabCount("rebuild", rebuildCount());
   }
   // Poll the state stores on a 1s tick to keep the pill counts in
   // sync. The state stores are mutated synchronously by every SSE