fix: bound detection QA to inference coverage

docs/API_CONTRACTS.md

@@ -893,7 +893,11 @@ Response persists a `quality_check` and `metrics` rows through the existing QA/Q
 Configured-YOLO QA automatically reads `tile_manifest_path` from the persisted
 `AnalysisRun.parameters_json`. Candidate and reference geometries are clipped
 to the union of the manifest's tile bounds after explicit CRS transformation to
-EPSG:4326. The response additionally returns:
+EPSG:4326. Before reference geometries are materialized, the service applies
+that coverage with an indexed PostGIS `ST_Intersects` predicate. The full
+dataset count is retained separately so raw/evaluated/excluded counts remain
+auditable without transferring a regional reference dataset to Python. The
+response additionally returns:
 
 - `candidate_feature_count_raw` and `reference_feature_count_raw`;
 - `coverage`, including raw/evaluated/excluded/boundary-clipped population