Read QA drawing evidence through the globe contract

Port the layer probes in twenty-six browser scripts to engine primitive
lists, drawn rows and layer diagnostics. Preserve Cesium as the reference
and keep the supported Navara paths on the same observations. This
changes QA observation only, with no application behaviour change.

Review the interrupted infrastructure group and retain its readiness,
drape, selection, label and floor checks. Match both installation outline
buffers. Frame each CCTV city before reading its visible coverage. Read
Radio colours and selected identities from actual mover writes. Retain
transit's GPU upload budgets using engine-owned line primitives rather
than substituting rebuild counts. Keep native inspection where a check
specifically measures GPU uploads, loaded meshes or ground readiness.

The preceding combined B/C commit owns all shared manifests, docs,
locale catalogs and the coupling baseline; this commit changes only its
own twenty-six QA scripts. Coupling remains unchanged at 344 Cesium
renderer lines, 1294 Navara renderer lines, 9 Cesium import files, 1026
viewer lines, 2 Navara kind checks, 0 engine sniff calls, 9 extension
reads, 1 ground pass, 3 SDK loads, 4 screen-handler files and 42 engine-name
lines.

The full unit suite and the boundary, format and coupling checks pass.
Browser validation remains to be run.

Browser checks to run
GOOGLE_MAPS_API_KEY= CESIUM_ION_TOKEN= npm run dev -- --port 4291
node scripts/qa-alpr-journey.mjs http://localhost:4291
node scripts/qa-alpr-journey.mjs 'http://localhost:4291/?engine=navara'
node scripts/qa-cables-overlay.mjs --url http://localhost:4291
node scripts/qa-cctv-v2.mjs --url http://localhost:4291 --fixture --terrain-globe
node scripts/qa-context-arrivals.mjs http://localhost:4291
node scripts/qa-directions.mjs --url http://localhost:4291
QA_BASE_URL=http://localhost:4291 node scripts/qa-draw-tool.mjs
QA_BASE_URL=http://localhost:4291 node scripts/qa-floor-hold.mjs
node scripts/qa-ghostmaps.mjs --url http://localhost:4291
node scripts/qa-gnss.mjs --url http://localhost:4291
node scripts/qa-height-datum.mjs --url http://localhost:4291
node scripts/qa-infra-lod.mjs --url http://localhost:4291
node scripts/qa-installation-navigation.mjs http://localhost:4291
node scripts/qa-military-names.mjs http://localhost:4291 --no-video
node scripts/qa-overpass-offload.mjs --url http://localhost:4291
node scripts/qa-radio.mjs --url http://localhost:4291
node scripts/qa-traffic-motion.mjs http://localhost:4291 --mode=osm
QA_BASE_URL=http://localhost:4291 node scripts/qa-transit-recovery.mjs
QA_BASE_URL=http://localhost:4291 node scripts/qa-transit.mjs
node scripts/qa-weather-teardown.mjs --url http://localhost:4291 --headless
for engine in cesium navara; do
  node scripts/qa-enrich-ambient.mjs --url http://localhost:4291 --engine=$engine
  QA_BASE_URL=http://localhost:4291 node scripts/qa-floor-verify.mjs --engine=$engine
  node scripts/qa-heading-b3.mjs --url http://localhost:4291 --engine=$engine
  node scripts/qa-overlay-baseline.mjs --url http://localhost:4291 --engine=$engine
  node scripts/qa-sprites-b5.mjs --url http://localhost:4291 --engine=$engine
  node scripts/qa-vessel-datum.mjs --url 'http://localhost:4291/?qaFeed=vessels:fixture' --engine $engine
done

The military-names driver exercises installation-polish; the transit
driver exercises transit-scenes. Use only the keyless server. Cases that
require photoreal tiles or unavailable providers remain unverified.

scripts/qa-floor-hold.mjs

@@ -172,19 +172,24 @@ const measure = () => page.evaluate(async (icao) => {
   }
   const v = app.viewer;
   const C = v.camera.positionCartographic.constructor;
-  const sprites = []; const models = []; let bb = null;
+  // The contact as the layer draws it (the probe's drawn rows: the layer owns
+  // no Cesium billboard of its own any more; the engine's batched billboards
+  // keep a hidden spare's old id, so an id match there can be stale).
+  const bb = app.layers.drawn('flights').find((row) => row.id === icao && !row.trackedModel);
+  if (!bb?.position) return { error: 'contact billboard not found' };
+  // Every billboard and model in the scene (the engine's mover batches
+  // included) stays out of the mesh probes.
+  const sprites = []; const models = [];
   const walk = (coll) => {
     for (let i = 0; i < coll.length; i++) {
       let p; try { p = coll.get(i); } catch { continue; }
       if (!p) continue;
       if (typeof p.length === 'number' && typeof p.get === 'function') { walk(p); continue; }
-      if (p.image !== undefined && p.alignedAxis !== undefined) {
-        sprites.push(p); if (p.id === icao) bb = p;
-      } else if (p.boundingSphere && p.modelMatrix) models.push(p);
+      if (p.image !== undefined && p.alignedAxis !== undefined) sprites.push(p);
+      else if (p.boundingSphere && p.modelMatrix) models.push(p);
     }
   };
   try { walk(v.scene.primitives); } catch { /* mid-teardown */ }
-  if (!bb?.position) return { error: 'contact billboard not found' };
   const carto = C.fromCartesian(bb.position);
   const lat = carto.latitude * 180 / Math.PI;
   const lon = carto.longitude * 180 / Math.PI;