_get_zoning() read non-existent props (top-level reg_numb_border / zone_code /
type_zone / name) so nspd_zoning.zone_code & zone_name were NULL on every parcel.
Real dump props (verified prod, 796 features) carry only the registration number,
duplicated across descr / label / externalKey / options.reg_numb_border (no human
zone name exists in the NSPD dump). Map both fields to that reg-number with safe
nested narrowing (isinstance options dict) + legacy fallbacks; honest — no
fabricated name. Surfacing reg_numb_border also unblocks the КСИТ crosswalk (#1843).
Regression tests use the real prop shape (full / nested-only / opaque→None).