Expand BWK nature data across Kempen

docs/DATA_SOURCES.md

@@ -445,3 +445,25 @@ Sprint 7B exposes provider metadata only. It does not perform GRB WFS calls, OSM
 | `fixture` | fixture | true | demo/test fixture layers | `dataset_role=reference`, `source_name=fixture` |
 
 Future provider output must flow through `DatasetService` and `VectorFeatureService`; providers must not write directly to `vector_features`.
+
+## Regional BWK/Natura 2000 state 2025
+
+`scripts/provision_regional_bwk_natura2000.py` expands the governed Mol
+operator to the approved 28-municipality Kempen transport-region scope. It
+queries the same official INBO `BWK:Bwkhab` WFS collection separately for each
+official VRBG municipality boundary. Every response is retained as a
+deterministic gzip artifact with both compressed-artifact and original-response
+SHA256 checksums.
+
+Geometry is intersected with each municipality in EPSG:31370 before it is
+transformed to EPSG:4326. Source polygons crossing a municipality boundary are
+therefore split into auditable pieces and receive a NIS suffix; those pieces
+must not be interpreted as independent source observations. The 28 validated
+partitions are assembled into one regional snapshot and persisted through the
+ordinary Dataset upload API with `source_name=inbo_bwk_natura2000`,
+`reference_layer_name=nature_value` and
+`temporal_series_key=inbo-bwk-natura2000:kempen-transport-region`.
+
+The state remains a single 2025 map edition, not an annual time series. BWK
+valuation, Natura 2000 shares, regional biotopes and uncertain habitat remain
+separate fields and metrics. PHAB-derived hectares remain explicitly estimated.