Measure engine coupling, QA harness use and contract coverage

Counters that may only fall, each with a committed baseline and a test
that fails on growth:

- report-engine-coupling.mjs gains layer modules that take the viewer
  in attachRenderer (33), layer folders with their own "view being
  restored" flag (9), engine.surface calls outside src/globe (41) and
  layer ids named in the engine switch (3).
- report-qa-harness.mjs counts QA scripts that launch Chrome themselves
  (98), wait with fixed sleeps (117), take the hidden loading screen as
  readiness (9), read Cesium-only objects (75) or define their own
  waitFor helpers (19).
- withCallLog records every contract member the contract suite calls on
  the fake engine; contractCoverage.test.mjs fails when a member outside
  contract-uncalled-baseline.json goes uncalled, and when a listed one
  is called now, so the list of 12 only shrinks.

scripts/engine-coupling-baseline.json

@@ -1,5 +1,9 @@
 {
   "metrics": {
+    "attachRendererWithViewer": 33,
+    "restoreFlagCopies": 9,
+    "surfaceCallsOutsideGlobe": 41,
+    "engineSwitchLayerIds": 3,
     "cesiumLayerRendererLines": 0,
     "navaraLayerRendererLines": 0,
     "cesiumImportFiles": 3,
@@ -11,6 +15,5 @@
     "cesiumSdkLoads": 3,
     "screenSpaceHandlerFiles": 2,
     "engineNameLines": 21
-  },
-  "measuredAt": "Orbital cockpit and bridge mesh sampling"
+  }
 }