feat: 出库类型贯穿申请→扫码出库——申请单加 outbound_type，申请时选类型、扫码出库自动带出

inventory-backend/app/services/outbound_service.py

@@ -701,7 +701,7 @@ class OutboundApprovalService:
         return f"APR-OUT-{date_str}-{time_str}-{sequence:04d}"
 
     @staticmethod
-    def create_request(applicant_id, items, allowed_approvers, remark=None, approver_id=None):
+    def create_request(applicant_id, items, allowed_approvers, remark=None, approver_id=None, outbound_type=None):
         """
         创建出库审批单（申请阶段，直接存储前端传来的物料信息快照，不关联具体库存记录）
 
@@ -759,6 +759,7 @@ class OutboundApprovalService:
             request_no=request_no,
             applicant_id=applicant_id,
             remark=remark,
+            outbound_type=outbound_type,  # 申请时确定的出库类型，扫码出库时带出
             status=0,  # 待审批
         )