Test layers on one engine and share selection and shader helpers

Layer display tests no longer re-check Cesium primitives in every layer:
they run on the fake engine, and one Cesium translation check per ground
kind lives in the Cesium engine's ground tests. Their harnesses are shared,
and the fake-engine, Cesium-engine and flights tests that repeated the
contract suite are gone, 340 tests in all.

The press-travel measurement is shared by the selection dispatcher and
CCTV, which loses its ScreenSpaceEventHandler shim and world-click module.
ALPR, installations and bikeshare share one selection keeper and selected
marker write. Layers with their own click rules keep their handlers.

Navara's pulse is a class like the ground pass, the ground and imagery
passes share the surface uniforms, and the colour, log-depth and occlusion
GLSL lives in one chunk module, each caller keeping its depth bias. The
ground suite runs inside the contract suite (--only=ground:), and fixture
and script names say what they test.

Behaviour is unchanged on both engines.

scripts/qa-gbfs-names.mjs

@@ -9,7 +9,7 @@ import fs from 'node:fs';
 import path from 'node:path';
 import puppeteer from 'puppeteer';
 import sharp from 'sharp';
-import { watchW1Page, redact } from './qa-browserEvidence.mjs';
+import { watchBrowserPage, redact } from './qa-browserEvidence.mjs';
 
 const urlIndex = process.argv.indexOf('--url');
 if (urlIndex < 0) throw new Error('An explicit --url is required');
@@ -87,7 +87,7 @@ async function open(mode = 'normal') {
   await page.bringToFront();
   const errors = [];
   if (extended)
-    watchW1Page(page, report, {
+    watchBrowserPage(page, report, {
       name: mode,
       baseUrl: appUrl,
       preview: process.argv.includes('--preview'),