feat(ui): render the status chips and their split-flap labels from a store

ShellFeedback publishes the loading status and the road network chip, and
CctvControls the camera grid chip, to the gev-status store; the scene
chrome renders them. SplitFlapText plays the departure-board cascade that
splitFlap.js plans, writing only the label's one text node, and rests when
its owner is destroyed. setSplitFlapText and disposeSplitFlap are gone.

src/radioMarkup.test.mjs

@@ -359,7 +359,6 @@ test('panel collapse is presentation-only and Radio exposes explicit voice playb
   assert.doesNotMatch(enableMethod, /contextRadio/);
   assert.match(enableMethod, /toggleRadio\(this\._radioEnableBtn\)/);
   assert.match(ui, /setAttribute\('aria-expanded', String\(/);
-  assert.match(readFileSync(new URL('./ui/shellFeedback.js', import.meta.url), 'utf8'), /\.hidden = !/);
   assert.doesNotMatch(method, /panelId === 'global-context-panel'[\s\S]*?this\._radioState\?\.enabled[\s\S]*?setPanelCollapsed\('radio-panel', false\)/);
 });