Add a new education entry to a candidate's profile. candidate_id is required; school, degree, and discipline are optional but must reference existing custom-field option ids (look these up via GET /v3/custom_field_options for the org's school_name, degree, and discipline custom fields, or create new options via POST /v3/custom_field_options first). Provide either start_date/end_date as ISO 8601 dates, or the month/year component pairs when only that granularity is known — the Greenhouse UI displays month-and-year regardless. Greenhouse recomputes latest automatically.