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-directions-engine-switch.mjs

@@ -1,19 +1,18 @@
 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';
 base.hash =
   'v=2&lat=55.3241&lon=10.7995&alt=25000&heading=0&pitch=-90&roll=0&map=sentinel2&l=';
 const strict = createStrict({ origin: base.origin, layers: ['directions'] });
-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);
   let routeReads = 0,
     release;
   await p.setRequestInterception(true);
@@ -55,21 +54,7 @@ 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,
-    );
-  };
-  await ready('navara');
+  await waitForEngine(p, 'navara');
   await p.evaluate(async () => {
     const { tileset, dataManager } = window.__godsEyeView;
     if (tileset || window.__GOOGLE_MAPS_API_KEY__)
@@ -91,8 +76,7 @@ await strict.run({ args: ['--use-angle=metal', '--enable-gpu'] }, async (b) => {
     'directions',
     'A and B set by clicks on the globe; one route request',
   );
-  await strict.pick(p, 'cesium');
-  await ready('cesium');
+  await strict.switchTo(p, 'cesium');
   release();
   await p.waitForFunction(() => window.qaRoute.getStats().count === 3);
   await p.waitForFunction(() => {
@@ -105,8 +89,7 @@ await strict.run({ args: ['--use-angle=metal', '--enable-gpu'] }, async (b) => {
     'the route asked for on Navara arrives on Cesium; a step is selectable',
   );
   const transfer = async (kind) => {
-    await strict.pick(p, kind);
-    await ready(kind);
+    await strict.switchTo(p, kind);
     assert.equal(
       await p.evaluate(
         () =>