error responses Shipped
What this lens looks for
RFC 9457 Problem Details format with Content-Type: application/problem+json; required fields: type (URI), title (stable), status (mirrors HTTP), detail (occurrence-specific), instance; extension fields (errors, trace_id) for machine-readable details
What its verifier checks
All error responses use application/problem+json content type; type field is a URI; status matches HTTP response code; field-level errors use errors array; no plain-string error bodies