feat(borrow): 借库未归还直接报废功能（关联报废单流程）

后端:
- trans_service 新增 scrap_borrow 方法：未归还借用标记为 scrapped，
  扣减总库存 stock_quantity（可用已在借出时冻结），生成 TransScrap 报废记录
- transactions.py 新增 POST /borrow/scrap 接口（复用 op_return:operation 权限，库管/主管可操作）
- scrap.py query_records 支持 trans_borrow 来源的物料名解析 + 行级隔离

前端:
- records.vue 未归还记录新增「报废」按钮（库管/主管可见）
- 报废弹窗：勾选明细 + 填报废原因 + 二次确认
- 状态显示新增「已报废」标签；整单所有明细报废时标记为 scrapped

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

@@ -356,7 +356,30 @@ class ScrapService:
             ).join(MaterialBase, TransRepair.base_id == MaterialBase.id).filter(
                 MaterialBase.company_name == company_limit
             )
-            all_matches = buy_subq.union(semi_subq, product_subq, repair_subq).subquery()
+            # ★ 借库转报废：stock_id 指向 trans_borrow.id，通过 borrow 关联源库存表再关联 MaterialBase
+            from app.models.transaction import TransBorrow
+            borrow_stock_buy = db.session.query(TransScrap.id).join(
+                TransBorrow, db.and_(TransScrap.stock_id == TransBorrow.id,
+                                     TransScrap.source_table == 'trans_borrow')
+            ).join(StockBuy, TransBorrow.stock_id == StockBuy.id).join(
+                MaterialBase, StockBuy.base_id == MaterialBase.id
+            ).filter(MaterialBase.company_name == company_limit)
+            borrow_stock_semi = db.session.query(TransScrap.id).join(
+                TransBorrow, db.and_(TransScrap.stock_id == TransBorrow.id,
+                                     TransScrap.source_table == 'trans_borrow')
+            ).join(StockSemi, TransBorrow.stock_id == StockSemi.id).join(
+                MaterialBase, StockSemi.base_id == MaterialBase.id
+            ).filter(MaterialBase.company_name == company_limit)
+            borrow_stock_product = db.session.query(TransScrap.id).join(
+                TransBorrow, db.and_(TransScrap.stock_id == TransBorrow.id,
+                                     TransScrap.source_table == 'trans_borrow')
+            ).join(StockProduct, TransBorrow.stock_id == StockProduct.id).join(
+                MaterialBase, StockProduct.base_id == MaterialBase.id
+            ).filter(MaterialBase.company_name == company_limit)
+            all_matches = buy_subq.union(
+                semi_subq, product_subq, repair_subq,
+                borrow_stock_buy, borrow_stock_semi, borrow_stock_product
+            ).subquery()
             query = query.filter(TransScrap.id.in_(all_matches))
 
         # 按时间倒序
@@ -390,7 +413,24 @@ class ScrapService:
             material_name = ''
             spec_model = ''
             
-            if r.source_table == 'trans_repair':
+            if r.source_table == 'trans_borrow':
+                # 借库转报废：stock_id 指向 trans_borrow.id，通过源库存表取物料
+                from app.models.transaction import TransBorrow
+                borrow = TransBorrow.query.get(r.stock_id)
+                if borrow:
+                    bstock_model = None
+                    if borrow.source_table == 'stock_buy':
+                        bstock_model = StockBuy.query.get(borrow.stock_id)
+                    elif borrow.source_table == 'stock_semi':
+                        bstock_model = StockSemi.query.get(borrow.stock_id)
+                    elif borrow.source_table == 'stock_product':
+                        bstock_model = StockProduct.query.get(borrow.stock_id)
+                    if bstock_model and hasattr(bstock_model, 'base_id') and bstock_model.base_id:
+                        base = MaterialBase.query.get(bstock_model.base_id)
+                        if base:
+                            material_name = base.name or ''
+                            spec_model = base.spec_model or ''
+            elif r.source_table == 'trans_repair':
                 # 维修单
                 repair = TransRepair.query.get(r.stock_id)
                 if repair: