Resolved in a grill-with-docs pass. recommend_lighting converts ALL non-LED
bulbs (incandescent + CFL + low-energy-unknown) to LED — all the way to LED, not
the legacy "fill to low energy", because SAP §12-1 rates LED efficacy (100)
above LEL (80) / CFL (55). A free Optimiser candidate (it improves SAP), unlike
ventilation's forced dependency. Its overlay is the first whole-dwelling,
top-level surface: a LightingOverlay carrying the four bulb-count fields by
their exact EPC names, folded directly onto EpcPropertyData (led=total, others
0). Priced per-bulb x non-LED count, contingency 0.26, measure_type
low_energy_lighting (MEASURE_MAP-aligned; "LED" in the description). Validation:
real before/after cascade pins (zero-existing-LEDs + some-existing-LEDs) at 1e-4,
clean (no fabric coupling). Ground-truth confirmed: 20 incandescent -> 20 LED
drops lighting (232) 783.7 -> 232.7 kWh/yr.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>