Record dated 75 AOI corpus iteration

docs/BELGIUM_BUILDING_TRAINING_LOOP.md

@@ -46,14 +46,14 @@ simultaneous gate.
 
 ## Current gap inventory
 
-The v3 corpus closes basic composition and leakage gaps with 60 independent
-AOIs and 10,262 accepted building labels. It adds coastal, ribbon-development,
-farmland, park, forest and additional urban contexts. Its remaining known gaps
-are:
+The v4 dated corpus closes basic composition, leakage and temporal-identity
+gaps with 75 independent AOIs and 13,765 accepted building labels. It adds
+coastal, ribbon-development, farmland, park, forest and additional urban
+contexts. Its remaining known gaps are:
 
-- all rolling regional mosaics have an unknown exact per-pixel observation
-  date; this is recorded honestly and must be resolved through dated provider
-  products or change-aware label review, never inferred from download time;
+- dated 2025 imagery is used for Flanders and Brussels and the dated 2024 SPW
+  campaign for Wallonia. Exact flight days remain a later metadata refinement,
+  but all corpus relations are now measured periods rather than download dates;
 - GRB/PICC/UrbIS describe ground footprints, whereas visible roofs can remain
   displaced. The existing detector QA contract therefore uses IoU 0.25; the
   threshold is frozen and cannot be relaxed per candidate;

docs/CODEX_EXECUTION_LOG.md

@@ -11554,3 +11554,19 @@ Next gate:
   for Flanders and Wallonia, and recorded one pure-empty false positive at the
   calibration-selected threshold. Training therefore continued on v3; no model
   was promoted and human review remains intentionally deferred.
+
+## 2026-07-27 - Dated imagery corpus v4 and loop continuation
+
+- Added governed, detection-capable fixed products for SPW Orthophotos 2024,
+  Digitaal Vlaanderen 2025 and its official Brussels coverage. Rolling
+  `latest` mosaics are no longer used by the training provisioner.
+- Expanded the corpus to 75 AOIs, with 15 training AOIs per region and the
+  protected validation/calibration/test/background composition unchanged.
+- Frozen corpus `building-be-v4-dated-20260727-r1` contains 13,765 accepted
+  labels from 13,899 inputs. Manifest SHA-256 is
+  `32f0c969e3131da33497ebffb6782ddf1b58e83b8a46f929818c2140af867fd3`.
+  Spatial leakage passed and temporal-unknown samples fell from 60 to zero.
+- Iteration 2 improved fixed-IoU test F1 from `0.375` to `0.419`; regional F1
+  became Brussels `0.566`, Wallonia `0.427`, Flanders `0.222`. The generic-base
+  iteration did not beat it. Both remained rejected, and iteration 4 started
+  from the stronger candidate on the dated 75-AOI corpus.

docs/TODO.md

@@ -953,4 +953,4 @@ This file now starts with the current implementation status. Older preparation/b
 - [x] Freeze the objective train/evaluate/error-analysis loop and regional exit gates.
 - [x] Expand the second corpus wave to 60 independent AOIs and 10,262 accepted labels.
 - [ ] Resolve the v3 Flanders and Wallonia generalisation failures through additional training-only evidence and retraining.
-- [ ] Replace unknown rolling-mosaic observation time with governed dated imagery where the regional provider exposes it; otherwise retain the explicit temporal limitation.
+- [x] Replace rolling-mosaic training inputs with governed dated 2025 Flanders/Brussels and 2024 SPW imagery; retain exact flight-day limitations.