BEGIN;

-- Audit evidence must survive an account deletion, but it must not block the
-- deletion or retain a recoverable administrator identity. Existing audit_log
-- rows are preserved; only the actor reference becomes NULL on deletion.
ALTER TABLE public.audit_log
  ALTER COLUMN admin_id DROP NOT NULL;

ALTER TABLE public.audit_log
  DROP CONSTRAINT IF EXISTS audit_log_admin_id_fkey;

ALTER TABLE public.audit_log
  ADD CONSTRAINT audit_log_admin_id_fkey
  FOREIGN KEY (admin_id)
  REFERENCES auth.users(id)
  ON DELETE SET NULL;

COMMIT;