fix(M03): support cold rendered ground sample startup

RENDER.md

@@ -937,6 +937,8 @@ $exe = Join-Path $env:TEMP 'godot-4.6.1-openwc\Godot_v4.6.1-stable_win64.exe'
 - `WorldRenderFacade.sample_ground_height()` accepts `GodotWorldPosition` and
   returns renderer-owned immutable `RenderedGroundSample` from already loaded
   quality/tile-LOD render meshes, avoiding a render-to-gameplay dependency.
+- Its factories load the predeclared Script path instead of relying on a warm
+  global-class cache; a dedicated cold-start verifier covers this bootstrap path.
 - `renderer_ground_query_snapshot()` preserves the terrain probe's tile readiness,
   queue position, mesh bounds and nearby seam-fallback diagnostics as a detached
   Dictionary; callers receive no queue, tile-state, Mesh or Node reference.