- approval_steps: parallel_group, acted_by, approval_type 컬럼 추가 - approvals: recall_reason, parent_doc_id 컬럼 추가 - approval_delegations 테이블 생성 (위임/대결)
- approval_steps: parallel_group, acted_by, approval_type 컬럼 추가 - approvals: recall_reason, parent_doc_id 컬럼 추가 - approval_delegations 테이블 생성 (위임/대결)