Slice 3c.1. Ingestion will persist a UPRN's coordinates and planning
protections together as a write-through cache, so resolve them in a single
partition read rather than two. `SpatialReference` bundles the coordinates
(which drive the Solar fetch) and the `PlanningRestrictions` (which gate wall
insulation per ADR-0019/ADR-0020); `GeospatialRepository.spatial_for(uprn)`
returns it, and `coordinates_for`/`planning_restrictions_for` now delegate to
the one lookup.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
