feat(map): share canonical Foundry presentation

docs/MAP_CESIUM_REACT_ADAPTER.md

@@ -8,6 +8,19 @@ Inspector fields, tokens, provider allowlists, TileCache storage or admin
 settings. A product supplies a same-origin BFF runtime contract and persisted
 provider-neutral view state.
 
+## Canonical presentation contract
+
+The adapter accepts the complete provider-neutral Map Page presentation state
+used by the Foundry `DC Default` profile: imagery color correction, globe and
+background colors, atmosphere, fog, sun, shadows, terrain exaggeration,
+building style/detail and the elevated grid with camera-height LOD. Consumers
+must persist and pass those values explicitly; the adapter does not invent a
+second product-specific visual profile.
+
+The canonical black-and-white scene keeps imagery enabled and sets imagery
+saturation to zero. `monochrome_enabled` is a separate solid-globe mode and
+must not be used as a substitute for the `DC Default` treatment.
+
 ## Security and runtime contract
 
 - The browser receives only same-origin BFF paths.
@@ -24,6 +37,11 @@ provider-neutral view state.
   yields a degraded scene when another provider remains ready.
 - Render-loop recovery is bounded to one request; a repeated fault becomes
   `cesium_render_error`.
+- Provider attribution is always registered with Cesium. An internal sandbox
+  may route the visual credit overlay into a hidden dedicated container only
+  through the explicit optional runtime flag
+  `sandbox.hide_credit_overlay=true`. The flag is absent or false by default
+  and must remain false for every external or production release.
 
 ## Asset delivery