fix: query persisted work area geometry

backend/app/api/routes/datasets.py

@@ -237,19 +237,32 @@ def select_vector_features(
         raise HTTPException(status_code=404, detail="Dataset not found")
     if dataset.dataset_type not in {"vector", "geojson"}:
         raise AppError(code="DATASET_NOT_VECTOR", message="Area selection requires a vector dataset", status_code=400)
-    result = VectorFeatureService.select_features_by_bbox(
-        db,
-        dataset_id=dataset_id,
-        bbox=payload.bbox.model_dump(),
-        limit=payload.limit,
-    )
-    if isinstance(dataset.source_metadata, dict) and dataset.source_metadata.get("selection_aggregation"):
-        result["summary"] = VectorFeatureService.summarize_features_by_bbox(
-            db,
-            dataset=dataset,
-            bbox=payload.bbox.model_dump(),
-            total_feature_count=result.get("total_feature_count"),
+    selection_area = None
+    if payload.area_id is not None:
+        selection_area = db.get(Area, payload.area_id)
+        if selection_area is None or selection_area.project_id != project_id:
+            raise AppError(code="AREA_NOT_FOUND", message="Area not found", status_code=404)
+
+    selection_kwargs = {
+        "dataset_id": dataset_id,
+        "bbox": payload.bbox.model_dump(),
+        "limit": payload.limit,
+    }
+    if selection_area is not None:
+        selection_kwargs.update(
+            selection_geometry=selection_area.geometry,
+            selection_area_id=selection_area.id,
         )
+    result = VectorFeatureService.select_features_by_bbox(db, **selection_kwargs)
+    if isinstance(dataset.source_metadata, dict) and dataset.source_metadata.get("selection_aggregation"):
+        summary_kwargs = {
+            "dataset": dataset,
+            "bbox": payload.bbox.model_dump(),
+            "total_feature_count": result.get("total_feature_count"),
+        }
+        if selection_area is not None:
+            summary_kwargs["selection_geometry"] = selection_area.geometry
+        result["summary"] = VectorFeatureService.summarize_features_by_bbox(db, **summary_kwargs)
     return envelope(VectorSelectionResponse(**result).model_dump(exclude_none=True))