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/ui/shellElements.js

@@ -100,18 +100,9 @@ export function readShellElements(document = globalThis.document) {
     _tiltMapBtn: document.getElementById('tilt-map-view'),
     _northUpBtn: document.getElementById('north-up-view'),
     _clearSelectedLayersBtn: document.getElementById('clear-selected-layers'),
-    _globalLoadingStatus: document.getElementById('global-loading-status'),
-    _globalLoadingLabel: document.getElementById('global-loading-label'),
-    _globalLoadingDetail: document.getElementById('global-loading-detail'),
     _resetGlobeBtn: document.getElementById('reset-globe-view'),
     _cockpitResetGlobeBtn: document.getElementById('cockpit-reset-globe'),
     _styleButtons: document.getElementById('style-buttons'),
-    _trafficSyncChip: document.getElementById('traffic-sync-chip'),
-    _trafficSyncLabel: document.getElementById('traffic-sync-label'),
-    _trafficSyncProgress: document.getElementById('traffic-sync-progress'),
-    _cctvSyncChip: document.getElementById('cctv-sync-chip'),
-    _cctvSyncLabel: document.getElementById('cctv-sync-label'),
-    _cctvSyncProgress: document.getElementById('cctv-sync-progress'),
     _toast: document.getElementById('toast'),
     _locationSearch: document.getElementById('location-search'),
     _searchToggle: document.getElementById('search-toggle'),