Electric-tariff cluster investigation. The 112-cert electric-main cohort is
mixed-sign within every category/meter - no systematic tariff bias. Root cause
of the biggest non-xfail divergences (10012334488 +13.2, 10091578598 +7.81):
SAP code 195 = 'Electric water storage boiler' (Table 4a p.170), which SAP 10.2
§12 Rule 2 correctly bills mostly at the 7-hour off-peak rate. Both are pure
cost gaps (PE/CO2 match lodged -> demand right); the lodged software over-billed
the storage boilers at peak rate. The engine is SPEC-FAITHFUL - matching lodged
would tune against §12/Table-4a. Pinned to the spec-faithful engine values.
Adds scripts/corpus_1000/elec_cohort.py (electric-main cohort analyzer).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
