Promote focused small-building detector

CHANGELOG.md

@@ -7,6 +7,16 @@
 
 # Changelog
 
+## Sprint 174 Focused small-building model promotion (2026-07-13)
+
+- Expanded the real operator corpus with four focused training AOIs and two independent validation AOIs, while keeping Turnhout, Retie and Westerlo outside the tile-training corpus as operation-level holdouts.
+- Exported and visually audited 198 tiles with 58,820 real GRB-derived labels; the accepted corpus contained no invalid labels, missing files or low-variance review selections.
+- Trained `geointel-building-yolov8s-smallbld-minpx3-img640-ft30-pt` from the previous active local model without downloading weights; the trained asset SHA256 is `a9088b8491dfae36694b53e9e9406cb4e3511d334a5712fa34f75078a47759c1`.
+- At tile `512`, overlap `64`, threshold `0.15` and QA match IoU `0.25`, seven persisted AOIs reached mean precision `0.5898`, recall `0.5770`, F1 `0.5825` and minimum F1 `0.5528`; all three pure-empty controls remained at zero detections.
+- Fixed-reference evidence reduced false negatives from 7,753 to 6,182, including 745 fewer 25-100 m2 misses and 181 fewer sub-25 m2 misses. Precision is lower, so the UI states the increased false-positive review load explicitly.
+- Added persistent false-negative area summaries/GeoJSON, explicit tile-corpus sample selection provenance, missing runtime evaluation scripts, Docker COPY-source regression checks and warning-free Pydantic model-field schemas.
+- Guarded activation updated only the Tower AI/model environment values; no fake outputs, provider fetching, API contract or database migration changed.
+
 ## Sprint 173 Expanded building model promotion (2026-07-13)
 
 - Trained and fully gated the inactive `geointel-building-yolov8s-aoi1024expandedminpx4vis035e50-pt` candidate from the 20-source expanded real-data corpus.