New price tier objective_geo_radius: ST_DWithin median of Objective new-build prices (objective_lots ⋈ complexes) within 3km of parcel centroid, between quarter-MV and district_reference. Closes the name-match gap (5 of 9 EKB districts had no Objective name-match). data/sql/168 functional GIST index (prod EXPLAIN 114ms→28ms). Degenerate-centroid guard + honest RU price_source captions. Deep-review ✅.
Refs #1881
