scoring.py adds the telescoping marginal cascade that serves two of the three
ADR-0016 scoring roles:
- marginal_impacts(scorer, baseline, overlays): applies overlays cumulatively
in order and reports each measure's marginal MeasureImpact (sap_points +
carbon/energy savings). Role 3 (final-package attribution) — the marginals
telescope EXACTLY to the whole-package total.
- independent_option_impacts(scorer, baseline, options): role 1 — scores each
Option's overlay independently vs baseline, scoring each DISTINCT overlay
once (Options sharing an overlay reuse the result). Approximate signal for
the optimiser; never surfaced as a measure's true impact.
Role 2 (whole-package re-score) is PackageScorer.score directly. Three
behaviour tests on the real Sap10Calculator / a counting stand-in (hand-built
EPD): single-overlay marginal == improvement-over-baseline; two-overlay
marginals telescope to the package total; per-Option dedup scores each
distinct overlay once. Closes#1156. pyright strict clean.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
