-- +goose Up
-- Clearance provenance, for honest and defensible ranking (subphase 2.18). The platform NEVER verifies
-- a clearance itself; the authoritative check is the hiring client FSO through DISS at onboarding. This
-- column records HOW a clearance is known so the UI and any ranking never imply a verification we cannot
-- perform. The default self_reported is the honest baseline for every existing and new candidate; an org
-- FSO can later mark a candidate sponsor_verified and stamp clearance_verified_at. Additive: no data is
-- rewritten, every current row defaults to self_reported.
ALTER TABLE candidates
  ADD COLUMN IF NOT EXISTS clearance_provenance text NOT NULL DEFAULT 'self_reported'
    CHECK (clearance_provenance IN ('self_reported', 'sponsor_verified', 'document', 'continuous_vetting'));
ALTER TABLE candidates
  ADD COLUMN IF NOT EXISTS clearance_verified_at timestamptz;

-- +goose Down
ALTER TABLE candidates DROP COLUMN IF EXISTS clearance_verified_at;
ALTER TABLE candidates DROP COLUMN IF EXISTS clearance_provenance;