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