The heating Recommendation Generator (HHRSH first). Emits one "Heating & Hot
Water" Recommendation whose competing whole-system bundles the Optimiser picks
from; this slice builds the high-heat-retention storage Option. Its overlay is
the absolute HHR end-state (Table 4a code 409 + control 2404 + dual off-peak
meter + off-peak electric cylinder), pinned against the relodged after-cert in
the next slice. Eligibility translates legacy is_high_heat_retention_valid to
structured predicates (electric or off-gas main, not already HHR/heat-pump).
mains_gas and the heat emitter are unchanged by the measure, so unset. ADR-0024.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
