Cut duplicated and dead code across the engines, the layers and the QA scripts

- src/geo drops the ported debug argument checks and the tests that
  bitExact already covers; package boundaries accept a directory entry,
  so src/geo/ is listed once per group.
- Cesium no longer carries movers and lines nobody draws with: they are
  optional engine capabilities. The fake engine and the Cesium camera use
  the shared cameraMath; unused contract tables, clock.ticked, the
  'finest' surface detail and Navara click statistics are gone.
- ALPR keeps one overlay core and one presentation model for both
  engines, bikeshare one station bookkeeping, the Navara ground effects
  one definition helper; image atlases, view centres, mover banks and
  colours are shared.
- The legacy switch route, the clock offset and rate controls and other
  unused exports are removed.
- The acceptance runs the Navara draw, geo import and scope checks;
  scenarios use the harness switch and page helpers; the main chunk
  check keeps the size budget only and runs once in CI.

scripts/qa-ground-layer-switch.mjs

@@ -1,7 +1,12 @@
 import { fromDegrees } from '../src/geo/cartesian3.js';
 import sharp from 'sharp';
 import assert from 'node:assert/strict';
-import { createStrict, localPreview } from './qa-strict-harness.mjs';
+import {
+  createStrict,
+  localPreview,
+  openPage,
+  waitForEngine,
+} from './qa-strict-harness.mjs';
 
 const base = localPreview(process.argv[2]);
 base.search = '?engine=navara&welcome=0&look=cinematic';
@@ -16,14 +21,8 @@ const strict = createStrict({
     'fire-perimeters',
   ],
 });
-await strict.run({ args: ['--use-angle=metal', '--enable-gpu'] }, async (b) => {
-  const p = await b.newPage();
-  await p.setViewport({ width: 1024, height: 768 });
-  const errors = [];
-  p.on('pageerror', (e) => {
-    errors.push(e.message);
-    console.log('error', e.message.split('?')[0]);
-  });
+await strict.run({}, async (b) => {
+  const { page: p, errors } = await openPage(b);
   await p.evaluateOnNewDocument(() => {
     const fetch = window.fetch.bind(window);
     window.fetch = (input, o) => {
@@ -122,20 +121,6 @@ await strict.run({ args: ['--use-angle=metal', '--enable-gpu'] }, async (b) => {
     };
   });
   await p.goto(base.href);
-  const ready = async (kind) => {
-    await p.waitForFunction(
-      (k) =>
-        window.__godsEyeView?.engine?.kind === k &&
-        !document.querySelector('#globe-engine')?.disabled &&
-        !document.querySelector('.engine-switch-frame') &&
-        document.querySelector('#loading-screen.hidden'),
-      { timeout: 90000 },
-      kind,
-    );
-    await p.evaluate(
-      () => window.__godsEyeView.styleManager.initialRestorePromise,
-    );
-  };
   const capture = async (visible, layerId = 'air-quality') => {
     await p.evaluate(
       async (show, id) => {
@@ -230,7 +215,7 @@ await strict.run({ args: ['--use-angle=metal', '--enable-gpu'] }, async (b) => {
     }
     return on;
   };
-  await ready('navara');
+  await waitForEngine(p, 'navara');
   await p.evaluate(() => {
     const d = window.__godsEyeView;
     if (d.tileset || window.__GOOGLE_MAPS_API_KEY__)
@@ -240,8 +225,7 @@ await strict.run({ args: ['--use-angle=metal', '--enable-gpu'] }, async (b) => {
   });
   for (const kind of ['navara', 'cesium', 'navara']) {
     if ((await p.evaluate(() => window.__godsEyeView.engine.kind)) !== kind) {
-      await strict.pick(p, kind);
-      await ready(kind);
+      await strict.switchTo(p, kind);
       const same = await p.evaluate(
         () =>
           window.__godsEyeView.dataManager.layers.get('air-quality').module ===
@@ -357,8 +341,7 @@ await strict.run({ args: ['--use-angle=metal', '--enable-gpu'] }, async (b) => {
   };
   for (const kind of ['navara', 'cesium', 'navara']) {
     if ((await p.evaluate(() => window.__godsEyeView.engine.kind)) !== kind) {
-      await strict.pick(p, kind);
-      await ready(kind);
+      await strict.switchTo(p, kind);
       await card(true);
       await strict.check(
         p,
@@ -478,8 +461,7 @@ await strict.run({ args: ['--use-angle=metal', '--enable-gpu'] }, async (b) => {
   let histories = await p.evaluate(() => window.qaVesselHistories);
   for (const kind of ['navara', 'cesium', 'navara']) {
     if ((await p.evaluate(() => window.__godsEyeView.engine.kind)) !== kind) {
-      await strict.pick(p, kind);
-      await ready(kind);
+      await strict.switchTo(p, kind);
     }
     const sample = await p.evaluate(() => {
       const entry =