fix: BOM草稿模块缺陷修复（事务回滚 + 外键约束 + 前端状态清理）

inventory-backend/app/api/v1/bom.py

@@ -1,6 +1,7 @@
 from flask import Blueprint, request, jsonify, current_app
 from sqlalchemy import or_
 from app.services.bom_service import BomService, _cache_delete
+from app.services.bom_draft_service import BomDraftService
 from app.models.base import MaterialBase
 from app.models.bom import BomTable
 from app.extensions import db
@@ -420,3 +421,61 @@ def get_cascade_inventory():
     except Exception as e:
         current_app.logger.error(f'级联库存计算失败: {str(e)}')
         return jsonify({'code': 500, 'msg': '内部服务器错误'}), 500
+
+
+# ==================== BOM 草稿接口 ====================
+
+@bom_bp.route('/draft/save', methods=['POST'])
+@jwt_required()
+def save_draft():
+    """暂存草稿"""
+    data = request.get_json()
+    bom_no = data.get('bom_no')
+    version = data.get('version', 'V1.0')
+    parent_id = data.get('parent_id')
+    children = data.get('children', [])
+
+    if not bom_no:
+        return jsonify({'code': 400, 'msg': 'bom_no 不能为空'}), 400
+    if not parent_id:
+        return jsonify({'code': 400, 'msg': 'parent_id 不能为空'}), 400
+
+    bom_draft_no = BomDraftService.save_draft(bom_no, version, parent_id, children)
+    return jsonify({'code': 200, 'msg': '草稿暂存成功', 'data': {'bom_no': bom_draft_no}})
+
+
+@bom_bp.route('/draft/detail', methods=['GET'])
+@jwt_required()
+def get_draft_detail():
+    """读取草稿详情"""
+    bom_no = request.args.get('bom_no')
+    version = request.args.get('version', 'V1.0')
+
+    if not bom_no:
+        return jsonify({'code': 400, 'msg': 'bom_no 不能为空'}), 400
+
+    draft = BomDraftService.get_draft_detail(bom_no, version)
+
+    # 【核心修改】：查不到草稿是正常现象，返回 HTTP 200 即可
+    if draft is None:
+        return jsonify({'code': 200, 'msg': '无草稿', 'data': None}), 200
+
+    return jsonify({'code': 200, 'msg': '查询成功', 'data': draft})
+
+
+@bom_bp.route('/draft/publish', methods=['POST'])
+@jwt_required()
+def publish_draft():
+    """发布草稿为正式 BOM"""
+    data = request.get_json()
+    bom_no = data.get('bom_no')
+    version = data.get('version', 'V1.0')
+
+    if not bom_no:
+        return jsonify({'code': 400, 'msg': 'bom_no 不能为空'}), 400
+
+    try:
+        bom_draft_no = BomDraftService.publish_draft(bom_no, version)
+        return jsonify({'code': 200, 'msg': 'BOM 发布成功', 'data': {'bom_no': bom_draft_no}})
+    except ValueError as e:
+        return jsonify({'code': 400, 'msg': str(e)}), 400