Add fail-closed source class and SAM fallback filters

scripts/normalize_belgium_building_labels.py

@@ -148,6 +148,7 @@ def normalize(
     reference_observed_at: str | None,
     imagery_valid_to: str | None = None,
     merge_touching_roofs: bool = False,
+    allowed_source_classes: set[str] | None = None,
 ) -> tuple[dict[str, Any], dict[str, Any]]:
     if source_name not in SUPPORTED_SOURCES:
         raise SystemExit(f"Unsupported governed building source: {source_name}")
@@ -184,6 +185,7 @@ def normalize(
                 "reason": None,
                 "geometry_repaired": False,
             }
+            source_class = decision["source_class"]
             source_creation_at = _source_creation_at(source_name, properties)
             decision["source_creation_at"] = source_creation_at.isoformat() if source_creation_at else None
             try:
@@ -199,6 +201,8 @@ def normalize(
             geometry = _polygonal(geometry)
             if geometry is None or geometry.is_empty or not geometry.is_valid:
                 decision["reason"] = "invalid_geometry_unrepairable"
+            elif allowed_source_classes is not None and source_class not in allowed_source_classes:
+                decision["reason"] = "source_class_not_allowed"
             elif (reason := _semantic_exclusion(properties)) is not None:
                 decision["reason"] = reason
             elif imagery_cutoff and source_creation_at and source_creation_at > imagery_cutoff:
@@ -276,6 +280,7 @@ def normalize(
         "accepted_source_feature_count": len(accepted),
         "accepted_feature_count": len(normalized_features),
         "merge_touching_roofs": merge_touching_roofs,
+        "allowed_source_classes": sorted(allowed_source_classes) if allowed_source_classes is not None else None,
         "decision_counts": dict(sorted(counts.items())),
         "decisions": decisions,
     }
@@ -294,6 +299,12 @@ def main() -> int:
     parser.add_argument("--reference-observed-at")
     parser.add_argument("--imagery-valid-to")
     parser.add_argument("--merge-touching-roofs", action="store_true")
+    parser.add_argument(
+        "--source-class",
+        action="append",
+        dest="source_classes",
+        help="Repeatable provider-native class allowlist. No cross-provider semantic mapping is inferred.",
+    )
     args = parser.parse_args()
     normalized, audit = normalize(
         reference_path=args.reference,
@@ -304,6 +315,7 @@ def main() -> int:
         reference_observed_at=args.reference_observed_at,
         imagery_valid_to=args.imagery_valid_to,
         merge_touching_roofs=args.merge_touching_roofs,
+        allowed_source_classes=set(args.source_classes) if args.source_classes else None,
     )
     args.output_reference.parent.mkdir(parents=True, exist_ok=True)
     args.output_audit.parent.mkdir(parents=True, exist_ok=True)