Slice 8 of the Solar PV Recommendation Generator (ADR-0026). The
ModellingOrchestrator now reads each Property's persisted Google Solar
buildingInsights JSON (uow.solar), projects it once per Property into a typed
SolarPotential via `_solar_potential_for` (None for a missing or error
payload), and threads it into `recommend_solar` alongside planning_restrictions
— mirroring the ASHP wiring. Solar fires only when a feasible potential is
present, so dwellings without fetched solar data are unaffected.
FakeSolarRepo now returns None for an unseeded Property (was raising) and
supports `by_property` seeding, so the orchestrator's new solar read is exercised.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
