Slice 3a (ADR-0020). PlanningRestrictions relocated out of the solid-wall
generator into domain/geospatial/ as the shared, Property-level value object
(three distinct flags + measure-specific blocks_external/blocks_internal).
GeospatialRepository gains a non-abstract planning_restrictions_for defaulting
to None (sources without the flags need not implement it); GeospatialS3Repository
reads conservation_status/is_listed_building/is_heritage_building from the same
Open-UPRN partition as the coordinates (legacy column names — to confirm in the
S3 deep-dive). Shared _row_for helper dedups the partition lookup.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
