docs(web-ui): document browser tab title call-count prefix

On refreshState, the hive-identity title update (fired once when
hive_name/swarm_name are configured) now reads any existing (N) prefix
and preserves it, so the title doesn't briefly drop back to the bare
identity string before refreshTabCounts re-applies the prefix.

docs/web-ui/dashboard.md

@@ -26,6 +26,16 @@ swap.
   `state.matrix_gui_enabled` from `/api/state`.
 - **Banner-thin** (`░▒▓█▓▒░ HYPERHIVE / HIVE-C0RE / WE ARE THE WIRED ░▒▓█▓▒░`)
   — sits below the tab strip.
+- **Browser tab title** — `hive / c0re` by default; updated to
+  `<swarm> / <hive>` once `hive_name` / `swarm_name` arrive in the
+  state snapshot. When there are pending approvals or unanswered
+  questions, a `(N)` prefix is prepended — `(3) pr1ma / hive-c0re`
+  — so the operator can see the call count in an unfocused browser
+  tab without opening the dashboard. The prefix is set on the
+  initial `/api/state` cold-load and updated live by
+  `approval_added` / `approval_resolved` / `question_added` /
+  `question_resolved` SSE events; it's preserved when
+  `hive_name` / `swarm_name` later replace the raw title.
 
 The FL0W page reuses the same chrome strip but its `◆ S3TT1NGS ◆ →`
 entry is a cross-page link back to the dashboard

frontend/packages/dashboard/src/tabs.js

@@ -3684,7 +3684,10 @@ window.marked = marked;
             : hive || swarm;
           hiveId.textContent = label;
           hiveId.hidden = false;
-          document.title = label + ' // h1ve-c0re';
+          // Preserve any (N) call-count prefix already applied by
+          // refreshTabCounts so the title doesn't flicker on reload.
+          const existingPrefix = document.title.match(/^(\(\d+\) )/)?.[1] || '';
+          document.title = existingPrefix + label + ' // h1ve-c0re';
         }
       }
       const openDetails = snapshotOpenDetails();
@@ -4036,6 +4039,12 @@ window.marked = marked;
       (approvalsState?.pending?.length ?? 0) +
       (questionsState?.pending?.length ?? 0);
     setTabCount('call', callCount);
+    // Browser tab title prefix — lets the operator see the pending
+    // call count without switching to the window. Strips any existing
+    // `(N) ` prefix before re-applying so identity-title updates
+    // (which run once on state load, not every tick) compose cleanly.
+    const rawTitle = document.title.replace(/^\(\d+\) /, '');
+    document.title = callCount > 0 ? `(${callCount}) ${rawTitle}` : rawTitle;
     // SYST3M — queued + running rebuild_queue entries (terminal
     // entries are kept for history but aren't 'attention').
     let sysCount = 0;