Get qualified regional Zillow context for a property

Requires API-key or first-party session authentication and a current account in the default-off server cohort. Valid current membership does not require a new paid subscription. Existing API quotas still apply. Responses are private, no-store. Unknown and repeated query parameters are rejected. This contract does not indicate source activation, deployment or an SDK release. Use-specific, unexpired reviewed Zillow rights are checked before parcel resolution or repository/cache access. Denied/unknown rights return explicit unavailable metric values, not substitute data. Each metric exposes actual regional geography/variant and freshness; regional values do not become parcel estimates or residual inputs. Only the trusted served parcel supplies ZIP/county/state. Caller-supplied geography/CBSA is rejected; there is no inferred metro match. canonical_id is omitted when rights prevent parcel lookup.