Complete live Mol register validation

docs/STORAGE_ARCHITECTURE.md

@@ -136,7 +136,7 @@ checksum conflict with an existing annual Dataset fails closed.
 Buildings and Addresses Register snapshot evidence lives under:
 
 ```text
-storage/operator-evidence/buildings-addresses-register/mol/{observed-date}/
+storage/operator-evidence/buildings-addresses-register/{area-key}/{observed-date}/
   raw/
     buildings_page_*.json
     building_units_page_*.json
@@ -153,6 +153,9 @@ counts and classified GRB reconciliation only. It enters PostGIS exclusively
 through DatasetService and ordinary `vector_features`; the operator never
 writes database rows directly. The manifest binds all raw pages, the normalized
 artifact, exact Area boundary and every GRB partition used for reconciliation.
+The Area key is deterministic (`mol`, `geel`, and so on). Reuse also requires
+the same Area label, observation date and boundary checksum, preventing one
+municipality's evidence from being imported under another Area.
 
 Offline demo export artifacts can be inspected and cleaned with: