container row: pending-reminder count chip (⏰ N)

ContainerView gains pending_reminders: u64; computed during
build_all via Broker::count_pending_reminders_for, mapping
manager → MANAGER_AGENT recipient + sub-agents → logical name.
Updates on every rescan (mutation sites + crash_watch's 10s
poll); accept 10s staleness on background remind / scheduler
delivery — live updates on operator cancel via /api/state path.

client renders a small cyan chip on the row when the count > 0;
tooltip points the operator at the reminders section to view
or cancel.

hive-c0re/assets/app.js

@@ -509,6 +509,14 @@
           { class: 'meta', title: 'sha currently locked in /meta/flake.lock' },
           `deployed:${c.deployed_sha}`));
       }
+      if (c.pending_reminders && c.pending_reminders > 0) {
+        head.append(el('span',
+          {
+            class: 'badge badge-reminder',
+            title: 'pending reminders queued for this agent — see the reminders section to view / cancel',
+          },
+          `⏰ ${c.pending_reminders}`));
+      }
       li.append(head);
 
       // ── line 2: action buttons ───────────────────────────────────