feat: scope detection QA to inference coverage

docs/AI_PIPELINES.md

@@ -544,6 +544,15 @@ Sprint 8C makes persisted detections reviewable:
 - Persisted detection geometries can be returned as GeoJSON FeatureCollections for MapLibre display.
 - Detection QA compares candidate detection geometries against persisted reference `vector_features`.
 - QA results reuse `quality_checks` and `metrics`; no parallel QA persistence system is introduced.
+- Configured-YOLO QA derives its evaluation extent from the persisted tile
+  manifest. Tile bounds are transformed from their explicit source CRS to
+  EPSG:4326, unioned, and used to clip candidate/reference populations before
+  canonical footprint-IoU matching. Reference features wholly outside the
+  imagery presented to the model no longer count as false negatives.
+- A separate reference-envelope IoU pass is persisted as
+  `box_to_footprint_diagnostics`. It quantifies possible matching artifacts from
+  comparing rectangular detections with irregular building footprints, but is
+  diagnostic only and never changes canonical QA metrics.
 - Segmentation remains out of scope for Sprint 8C.
 
 ## 2. Tile Metadata