block checkpoint evaluation on ancestral exposure

docs/CODEX_EXECUTION_LOG.md

@@ -12737,3 +12737,37 @@ Open:
 - Independent real-background AOIs are still required. Literal 100% model
   correctness is not demonstrated; the system now refuses to misrepresent the
   known overlap as proof.
+
+## 2026-08-09 - Full ancestral-corpus exposure correction
+
+### Corrected
+
+- Reconstructed the retained checkpoint ancestry from exact Ultralytics
+  `args.yaml` files and model hashes. The active model descends from the
+  expanded-min4 corpus; the challenger descends from the active model.
+- Found that the expanded ancestor used Postel-bos for training and
+  Turnhout/Westerlo for validation. All three v69 evaluation AOIs were therefore
+  exposed somewhere in the model family.
+- Replaced last-corpus/train-only checking with fail-closed inspection of every
+  split in every supplied ancestral corpus. Legacy CLI spellings remain safe
+  aliases to the full-lineage behavior.
+
+### Verified
+
+- The Tower gate blocked all three exposed AOIs with zero model-loading and
+  zero GPU-inference attempts.
+- Expanded ancestor summary SHA-256:
+  `1887e2ba5c719d33675a9ed85db99a274fd66d98d5f6ad44558d673620917201`.
+- Blocked-manifest SHA-256:
+  `f6effd94befd6df8d699bc66fbbea8a860b056cff9996be5f867f858807af65e`.
+- Model-lineage receipt SHA-256:
+  `84d8d7bd95acfb07b188b07ececfc5417fca80c087d7c04442dd2a4da5f43936`;
+  every retained training `best.pt` matches its named model copy byte-for-byte.
+- The production checkpoint and container image remain unchanged.
+
+### Accuracy boundary
+
+- The old Turnhout/Westerlo/Postel numbers are regression diagnostics only.
+  No independent positive or background accuracy evidence currently exists for
+  this model family; new AOIs must be provisioned without ancestry or spatial
+  exposure before another ranking is defensible.