Merge origin/main into german/navara

Brings in 190 commits from main. Integration on the engine contract:

- News and Shipwrecks draw, pick and keep their selection through the
  contract and shared map markers, so they follow engine switches.
- Aircraft tracking uses main's segmented trails with contract frame
  numbers.
- Decoded weather tiles move into the Cesium adapter and are injected
  through the renderer registry; Navara hides those sources on globe
  surfaces (docs/KNOWN-ISSUES.md).
- Street-vehicle GPU depth occlusion stays Cesium-only; Navara keeps
  the geometric visibility checks (docs/KNOWN-ISSUES.md).
- Transit includes the heading-neutral atlas icons.

scripts/engine-coupling-baseline.json

@@ -7,10 +7,10 @@
     "cesiumLayerRendererLines": 0,
     "navaraLayerRendererLines": 0,
     "cesiumImportFiles": 2,
-    "viewerLines": 613,
+    "viewerLines": 632,
     "navaraKindChecks": 1,
     "engineSniffCalls": 0,
-    "engineExtensionReads": 2,
+    "engineExtensionReads": 4,
     "groundEffectPasses": 0,
     "cesiumSdkLoads": 3,
     "screenSpaceHandlerFiles": 2,