Run the Navara paths without the Cesium SDK, and load it on demand for the features that still build on it

Every Cesium read that a Navara page made was surveyed with the strict acceptance (GEV_QA_CESIUM_TRAP=record). Math on those paths now uses src/geo: screen annotations, weather and wind center readings, cyclone picks, scene data pack polygons and images (new navaraGeometry.js), the awareness subject, the orbit offset of camera verbs, voice frame_overhead, the agent world packet and Directions colours and ground picks. The celestial ring's Sun and Moon come from a bit-identical port of Cesium's Simon1994 model, JulianDate and TEME rotation (src/geo/simon1994.js, julianDate.js, transforms.js); a Cesium globe still applies its ICRF rotation once loaded.

Traffic, Street Level, the Nepal event and locator and geo import build on Cesium's math or entity model on either globe; their enable (or the import) now loads the SDK first through src/app/loadCesium.js, synchronously when it is already there. A production page guards the global so a missed read is reported and starts the load. No module reads Cesium while it loads (scripts/check-cesium-load-time.mjs, run by npm test). Cesium.js is still loaded by index.html here.

scripts/check-cesium-load-time.test.mjs

@@ -0,0 +1,42 @@
+import assert from 'node:assert/strict';
+import { readFileSync } from 'node:fs';
+import test from 'node:test';
+import { loadTimeReferences, sourceFiles } from './check-cesium-load-time.mjs';
+
+const reads = (code) =>
+  loadTimeReferences(code).map(({ line, name }) => `${line}:${name}`);
+
+test('reads that run while a module loads are found; reads inside later code are not', () => {
+  assert.deepEqual(
+    reads(`import * as Cesium from 'cesium';
+const color = Cesium.Color.RED;
+export function later() { return Cesium.Color.BLUE; }
+const lazy = () => Cesium.Math.PI;
+class Shape { static axis = Cesium.Axis.Y; field = Cesium.Axis.Z; draw() { return Cesium; } }
+(() => Cesium.VERSION)();
+export const fallback = (sdk = Cesium) => sdk;`),
+    ['2:Cesium', '5:Cesium', '6:Cesium'],
+  );
+  assert.deepEqual(
+    reads(`import { Cartesian3 as C3, Color } from 'cesium';
+export const ORIGIN = C3.ZERO;
+export function white() { return Color.WHITE; }`),
+    ['2:C3'],
+  );
+  assert.deepEqual(reads(`export { Axis } from 'cesium';`), [
+    '1:export from cesium',
+  ]);
+  assert.deepEqual(
+    reads(`window.__CESIUM__ = Cesium;`),
+    ['1:Cesium'],
+    'the global counts where the module does not import it',
+  );
+  assert.deepEqual(reads(`const geo = { Cesium: 1 }; geo.Cesium;`), []);
+});
+
+test('no shipped module reads Cesium while it loads', () => {
+  const found = sourceFiles().flatMap((path) =>
+    loadTimeReferences(readFileSync(path, 'utf8'), path),
+  );
+  assert.deepEqual(found, []);
+});