feat: add governed Mol nature value layer

docs/API_CONTRACTS.md

@@ -496,6 +496,11 @@ Rules:
 - Results are generated from persisted PostGIS `vector_features`, not from client-side map data.
 - `feature_count` is the number of GeoJSON features returned in the bounded preview. `total_feature_count` is the exact number of persisted rows intersecting the requested bbox or persisted Area geometry.
 - `summary` keeps one backwards-compatible primary metric and exposes all relevant measurements in `metrics`. Known themes use metric PostGIS calculations: building/forest/water/parcel surfaces in hectares, road and watercourse lengths in kilometres, population in inhabitants and intersecting feature counts as supporting evidence.
+- Governed datasets may declare additional `source_metadata.selection_metrics`.
+  Each metric may constrain one persisted feature-property to an explicit value
+  allowlist before the same PostGIS aggregation runs. The BWK/Natura 2000
+  dataset uses this only for official `EVAL` classes; it does not collapse mixed
+  classes into a made-up score.
 - Area and length calculations transform geometry to Belgian Lambert 72 (`EPSG:31370`); they are never calculated in geographic degrees.
 - Water volume is not inferred from 2D GRB geometry. It remains unavailable until a source provides reliable depth or bathymetry with compatible spatial coverage and provenance.
 - The response is capped by `limit` and returns `truncated=true` when `total_feature_count` exceeds the returned preview.
@@ -1582,6 +1587,9 @@ aggregation method, feature count, estimate status and an optional warning.
 Supported PostGIS aggregations are feature count, intersection area,
 intersection length, numeric sum and area-weighted numeric sum. Area and length
 are measured after transformation to EPSG:31370.
+Configured supplemental metrics can use `filter_property` plus
+`filter_values`. Filters are server-owned dataset metadata, not arbitrary
+client SQL or request expressions.
 
 ### PATCH `/api/v1/projects/{project_id}/datasets/{dataset_id}/temporal`
 

docs/DATA_SOURCES.md

@@ -227,6 +227,27 @@ until a governed operator import, provenance record and validation pass exist.
   LiDAR, suitable for elevation, slope and drainage. It does not provide water
   depth.
 
+## Governed BWK and Natura 2000 state 2025
+
+`scripts/provision_mol_bwk_natura2000.py` uses the official production WFS
+`https://geo.api.vlaanderen.be/BWK/wfs`, feature type `BWK:Bwkhab`. It follows
+server `next` links and uses WFS `startIndex` only when a full page omits that
+link. A short final page is required for completeness. Raw response pages,
+request URLs and SHA256 checksums are retained.
+
+The source bbox is reduced to the exact persisted Mol Area in Belgian Lambert
+72. Only valid polygonal intersections are emitted, transformed back to
+EPSG:4326 and imported through DatasetService with `source_name` equal to
+`inbo_bwk_natura2000` and `reference_layer_name` equal to `nature_value`.
+Required attribution is `Bron: INBO`.
+
+`EVAL` classes are reported separately. Natura 2000 and regionally important
+biotope hectares use official `PHAB` shares; uncertain `ohab` polygons remain
+knowledge gaps. The official report warns that parts of the 2025 edition,
+especially outside Habitats Directive areas, can still be based on older
+mapping. GeoIntel therefore preserves origin fields and never presents this
+single edition as a historical trend.
+
 ## Governed Waterinfo station history
 
 `scripts/provision_waterinfo_station_history.py` uses the public Waterinfo

docs/DATA_SPECIFICATION.md

@@ -213,6 +213,21 @@ series may not be merged into one area-wide value. Point water level and
 discharge may not be converted to water volume without governed compatible
 depth/profile data.
 
+### BWK and Natura 2000 polygons
+
+The governed state-2025 import uses `BWK:Bwkhab` polygons. Geometry is fetched
+in EPSG:4326, validated and clipped against the persisted Mol boundary in
+EPSG:31370, then persisted in EPSG:4326. Required retained fields include
+`EVAL`, `EENH1..8`, `V1..3`, `HERK`, `BWKLABEL`, `HAB1..5`, `PHAB1..5`,
+`HERKHAB`, `HERKPHAB` and `HABLEGENDE`.
+
+BWK value classes remain independent. Natura 2000 codes, regionally important
+biotope codes and uncertain `ohab` knowledge gaps are also independent. PHAB
+shares can be theoretical source allocations; derived hectares therefore keep
+an estimate warning, especially for partial rectangle intersections. State
+2025 is a product edition and must not be presented as a uniform 2025 field
+survey or an annual time series.
+
 ### Vector
 
 Ondersteund:

docs/STORAGE_ARCHITECTURE.md

@@ -109,6 +109,13 @@ product/layer, request/spatial hash, temporal validity and limitations are held
 in source/provenance metadata. Browser PNG rendering is derived on request and
 does not replace the stored GeoTIFF.
 
+BWK/Natura 2000 evidence lives under
+`storage/operator-evidence/bwk-natura2000-2025/mol/`. The `raw/` directory
+contains immutable WFS pages; the adjacent manifest records their URLs,
+checksums, boundary checksum, page/feature counts, clipping diagnostics and
+official class totals. The final GeoJSON is the retained source artifact while
+`datasets` and `vector_features` remain the canonical queryable PostGIS state.
+
 Offline demo export artifacts can be inspected and cleaned with:
 
 ```bash