Close reasons are the organization-defined dictionary of outcomes recorded when an opening is closed (e.g. Hire - New Headcount, Hire - Backfill, On Hold, Not Filling). Each closed opening references a single close reason via close_reason_id; resolve the human-readable label here. Customized per organization under Configure > Custom Options > Close Reasons for Job Openings, so the available set varies between Greenhouse accounts. Distinct from rejection_reasons, which apply to candidate applications rather than to openings.