evaluate models on fresh regional calibration AOIs

docs/reviews/2026-08-09-ai-assisted-checkpoint-review.md

@@ -263,3 +263,41 @@ The byte-matching parent/output chain is retained separately in
 `artifacts/evidence/accuracy/model-training/20260809-v71-model-lineage-receipt.json`.
 Fresh geographically separated AOIs with complete spatial and lineage checks
 are required for the next meaningful evaluation.
+
+## Fresh V72 calibration portfolio
+
+Six AOIs were pre-registered before inference and acquired again from the
+governed regional orthophoto and building adapters: two each in Vlaanderen,
+Wallonië and Brussel. All six are absent from every split of the retained model
+lineage. A raster-bound spatial audit resolved all 31 ancestral AOIs and found
+the nearest new AOI at 4,869.63 metres, above the frozen 2 km floor.
+
+The initial generic edge-cover tiling would have counted 54 tiles because its
+final-row/final-column coverage nearly duplicated the preceding 512 px cells.
+That view was rejected. The corrected evaluation-only exporter retains exactly
+24 full grid cells, excludes 30 overlapping edge-cover views with reason codes,
+and writes no training tiles. Both the corpus and tile view contain bound
+`NO_TRAINING.json` markers.
+
+All 24 tiles and 348 retained labels were visually inspected. Havelange is a
+positive village context despite its pre-registered `field-cal-bg` name.
+Assenede and Laeken contain sparse official building labels and are difficult
+contexts, not pure-empty backgrounds. The evaluator now refuses to accept a
+pure-background prefix when any corresponding label file is non-empty.
+
+On the RTX 4080 SUPER the active model scores mAP50 `0.056779` and mAP50-95
+`0.021750`; the challenger scores `0.044705` and `0.016004`. At confidence 0.25
+and match IoU 0.25 their F1 scores are `0.231527` and `0.235885`. These low
+values expose substantial domain-generalisation failure. The active model stays
+in production because the challenger has weaker mAP, only a marginal F1 gain,
+missing historical release provenance and no valid promotion bundle.
+
+The active model's aggregate calibration F1 peaks at threshold 0.30
+(`0.250356`), but its Flemish subgroup becomes worse than at lower thresholds.
+No threshold was changed because a global average may not mask that subgroup
+regression. PICC and UrbIS remain diagnostic-only while their regional semantic
+harmonisation contracts are pending; no national release claim is made.
+
+Complete evidence is retained under
+`artifacts/evidence/accuracy/model-training/20260809-v72-fresh-calibration/`
+and summarized by `20260809-v72-fresh-calibration-summary.json`.