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-cctv-engine-switch.mjs

@@ -37,7 +37,7 @@ const { stdout: video } = await promisify(execFile)(
   { encoding: 'buffer', maxBuffer: 16000000 },
 );
 const strict = createStrict({ origin: url.origin, layers: ['cctv'] });
-await strict.run({ args: ['--use-angle=metal', '--enable-gpu'] }, async (b) => {
+await strict.run({}, async (b) => {
   const p = await b.newPage();
   const errors = [];
   p.on('pageerror', (e) => {