feat: operationalize Flemish land and nature themes

docs/API_CONTRACTS.md

@@ -2195,3 +2195,51 @@ return an empty, honest result. No provider request occurs during analysis.
 Future provider output continues to use DatasetService and, for vectors,
 VectorFeatureService. Arbitrary service URLs, browser-side fetches, insecure
 TLS bypasses and startup downloads remain forbidden.
+## Governed official nature and soil acquisition
+
+### GET `/api/v1/projects/{project_id}/datasets/official-vector/products`
+
+Returns the fixed official vector registry in the canonical `{ "data": ... }`
+envelope. The allowlist contains `bwk_natura2000_2025` and `dov_soil_types`;
+arbitrary collection names or URLs are never accepted.
+
+### POST `/api/v1/projects/{project_id}/datasets/official-vector/acquire`
+
+Request:
+
+```json
+{
+  "bbox": {
+    "min_x": 5.05,
+    "min_y": 51.15,
+    "max_x": 5.25,
+    "max_y": 51.30,
+    "crs": "EPSG:4326"
+  },
+  "area_id": "optional-area-uuid",
+  "product_key": "bwk_natura2000_2025",
+  "force_refresh": false
+}
+```
+
+The synchronous `vector.official.acquire` Job validates the metric request
+size, intersects `bbox` with the persisted Area, retrieves every bounded page,
+clips polygon geometry in EPSG:31370 and persists EPSG:4326 features through
+`DatasetService`. A repeated exact request can reuse the 24-hour cache.
+Provider errors, unstable or incomplete WFS pagination and safety-limit violations
+fail without persisting a truncated Dataset.
+
+`bwk_natura2000_2025` preserves BWK `EVAL`, `EENH*`, `HAB*` and `PHAB*`
+semantics. `dov_soil_types` preserves mapped soil, texture, drainage, profile
+and substrate classes and is dated as the 1949-1971 survey period. Neither
+contract accepts a caller-supplied endpoint.
+
+## Governed Landgebruik Vlaanderen forest and agriculture
+
+The existing
+`GET /api/v1/projects/{project_id}/datasets/thematic-raster/products` registry
+also returns `forest_land_use_2025` for source class 12 and
+`agricultural_land_use_2025` for source classes 13 and 14. Both use the
+existing thematic acquisition and selection contracts. Persisted rasters are
+binary masks; the source class allowlist and original source-value range are
+retained and validated.