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-floor-verify.mjs

@@ -11,7 +11,7 @@ import fs from 'node:fs';
 // QA_BASE_URL matches the sibling harnesses (qa-height-datum / qa-cctv-v2) so a
 // secondary checkout can verify against its own dev server instead of the default :4173.
 const BASE_URL = process.env.QA_BASE_URL || 'http://localhost:4173';
-// --engine=cesium|navara (phase 3): on Navara the camera, the mesh probes and
+// --engine=cesium|navara: on Navara the camera, the mesh probes and
 // the sprite census go through the engine and the QA probe.
 const ENGINE = (process.argv.find((arg) => arg.startsWith('--engine=')) ?? '--engine=cesium').slice(9);
 const APP_URL =
@@ -125,7 +125,7 @@ const report = await page.evaluate(async () => {
         drawnBy: modelAt ? 'model' : 'sprite',
         meshM: meshH != null ? +meshH.toFixed(1) : null,
         aboveMeshM: meshH != null ? +(c.height - meshH).toFixed(1) : null,
-        // Why a contact sits where it does (10b review 6): the probe's own
+        // Why a contact sits where it does: the probe's own
         // answer (source, tile size) and the coarse DEM floor (the prior).
         probe: answer ? { source: answer.source, tileSizeM: answer.tileSizeM ?? null } : null,
         demFloorM: cachedGroundFloor(c.latitude * 180 / Math.PI, c.longitude * 180 / Math.PI) ?? null,