feat(ui): render the FPS readout in the title bar from the status store

createFrameRateMonitor() keeps the key, frame count and interval and
publishes the readout to the gev-status store; the scene chrome renders
it after the subtitle with the same class, hidden state and title. A
page without the title bar still gets no monitor, and a monitor only
updates or withdraws the readout the store shows.

scripts/format-scope.json

@@ -530,6 +530,7 @@
   "scripts/qa-traffic-navigation.mjs",
   "src/ui/frameRateMonitor.js",
   "src/ui/frameRateMonitor.test.mjs",
+  "src/ui/frameRateView.test.mjs",
   "src/layers/cctv/lifecycle.js",
   "src/layers/cctv/controls.js",
   "src/layers/cctv/geometry.js",