feat: 出库/借库记录记录并展示库位快照（DB加列+后端写入+记录页展示）

inventory-backend/app/models/outbound.py

@@ -133,6 +133,9 @@ class TransOutbound(db.Model):
     outbound_time = db.Column(db.DateTime, default=beijing_time)
     operator_name = db.Column(db.String(100))  # 操作员
 
+    # [新增] 出库时的库位快照（从源库存记录带出，便于历史追溯）
+    warehouse_location = db.Column(db.String(100))
+
     remark = db.Column(db.Text)
 
     def to_dict(self):
@@ -148,5 +151,6 @@ class TransOutbound(db.Model):
             'signature_path': self.signature_path,
             'outbound_time': self.outbound_time.strftime('%Y-%m-%d %H:%M:%S') if self.outbound_time else None,
             'operator_name': self.operator_name,
+            'warehouse_location': self.warehouse_location or '',
             'remark': self.remark
         }

inventory-backend/app/models/transaction.py

@@ -23,6 +23,8 @@ class TransBorrow(db.Model):
     return_operator = db.Column(db.String(100))
     return_signature = db.Column(db.Text)
     return_location = db.Column(db.String(100))
+    # [新增] 借出时的库位快照（从源库存记录带出，便于历史追溯）
+    location = db.Column(db.String(100))
     status = db.Column(db.String(20), default='borrowed')
     remark = db.Column(db.Text)
 
@@ -49,6 +51,7 @@ class TransBorrow(db.Model):
             'return_operator': self.return_operator,
             'return_signature': self.return_signature,
             'return_location': self.return_location,
+            'location': self.location or '',
             'status': self.status,
             'remark': self.remark,
         }

inventory-backend/app/services/outbound_service.py

@@ -278,6 +278,8 @@ class OutboundService:
                     quantity=quantity,
                     unit_price=unit_price,
                     outbound_time=current_time,
+                    # [新增] 记录出库时的库位快照
+                    warehouse_location=getattr(stock_record, 'warehouse_location', None),
                     **common_data
                 )
                 db.session.add(new_record)
@@ -647,7 +649,9 @@ class OutboundService:
                 'quantity': qty,
                 'unit_price': price,
                 'subtotal': subtotal,
-                'batch_sn': batch_sn
+                'batch_sn': batch_sn,
+                # [新增] 出库时的库位快照（展示用）
+                'warehouse_location': getattr(d, 'warehouse_location', None) or ''
             })
 
         # 4. 排序输出

inventory-backend/app/services/trans_service.py

@@ -152,6 +152,8 @@ class TransService:
                     borrow_signature=signature,
                     remark=remark,
                     expected_return_time=expected_return_time,
+                    # [新增] 记录借出时的库位快照
+                    location=getattr(stock, 'warehouse_location', None),
                     status='borrowed',
                     is_returned=False
                 )