Adds services/ml_training_data/src/ml_training_data/sap_parity_probe.py
— samples N certs from the v18a corpus, streams them via BulkZipReader,
runs Sap10Calculator, prints MAE/RMSE/bias + worst-N residuals. Baseline
across 100 certs: MAE 8.41, RMSE 13.98, bias -2.65, 0 errors.
docs/sap-spec/PARITY_FINDINGS.md captures the dominant failure pattern
(flats + bungalows under-predicted, 10 of the worst-15 are flats whose
floor/roof are party with neighbouring dwellings) and the priority-
ordered Session B iteration backlog (S-B-flat-surfaces first).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
