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/loadingFeedback.test.mjs

@@ -209,7 +209,7 @@ test('universal notice lifecycle clears on dispose and uses the one top-center l
   const disposeEnd = ui.indexOf('\n  }\n', disposeStart);
   const dispose = ui.slice(disposeStart, disposeEnd);
 
-  assert.match(dispose, /this\._feedback\._globalStatusNotice = null;/);
+  assert.match(dispose, /this\._feedback\.clearLoadingStatus\(\);/);
   assert.match(dispose, /this\._shareRestoration\.destroy\(\)/);
   assert.match(ShareRestoration.prototype.destroy.toString(), /this\._shareTrackingNoticeGeneration \+= 1;/);
   assert.match(html, /<div id="global-loading-status" role="status" aria-live="polite" aria-atomic="true" hidden>/);
@@ -539,20 +539,10 @@ test('the settled traffic chip shows exactly one percentage — the coverage it
   assert.doesNotMatch(rendered, /100%/);
 });
 
-test('the chip renderer clears the progress slot instead of stranding the last value', () => {
-  const ui = readFileSync(new URL('./ui/shellFeedback.js', import.meta.url), 'utf8');
+test('an emptied progress slot collapses rather than leaving a min-width stub', () => {
+  // ShellFeedback publishes the empty settled progress
+  // (src/ui/statusChipOwners.test.mjs); the slot must then take no room.
   const css = readStylesheet(new URL('../style.css', import.meta.url));
-  const start = ui.indexOf('  _updateTrafficSyncChip(');
-  assert.ok(start > 0, '_updateTrafficSyncChip is missing');
-  const body = ui.slice(start, ui.indexOf('\n  }', start));
-  // A truthiness guard here would leave the busy "..." sitting beside the
-  // settled label, which is the contradiction wearing a different hat.
-  assert.doesNotMatch(body, /if \(presentation\.progressText\s*\n?\s*&&/);
-  assert.match(
-    body,
-    /if \(this\._trafficSyncProgress\.textContent !== presentation\.progressText\) \{/,
-  );
-  // …and the emptied slot must collapse rather than leave a min-width stub.
   assert.match(css, /#traffic-sync-progress:empty \{\s*display: none;\s*\}/);
 });