Separate vessel records and acquisition from scene resources

docs/CODE-BOUNDARIES.md

@@ -497,3 +497,9 @@ ownership boundary. Military observations retain their aviation-foot readout,
 source-time fallback and model-owned ground policy. The renderer supplies that
 ownership fact and handles stale-ground lifting, Cesium history and primitives;
 record reconciliation does not import the engine or application.
+
+`layers/vessels/records` owns plain AIS metadata, stable MMSI identity and bounded
+retention. `layers/vessels/ingestion` owns source requests and feed state through
+explicit operations. Both exports exclude Cesium, DOM and application assembly.
+The snapshot renderer applies record changes; rendering owns a weak map of
+geometry and billboard resources used by cards, picking and trails.