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:

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

@@ -110,6 +110,38 @@ def submit_return():
         return jsonify({'code': 400, 'msg': str(e)}), 400
 
 
+# --- 借库报废（未归还直接报废，关联报废单流程）---
+@trans_bp.route('/borrow/scrap', methods=['POST'])
+@jwt_required()
+@permission_required('op_return:operation')  # 复用归还权限：能归还的库管即可报废
+@audit_log(
+    module='借库管理',
+    action='借库报废',
+    get_target_name_fn=lambda: request.get_json().get('reason') if request.get_json() else None
+)
+def scrap_borrow():
+    """
+    借库未归还直接报废（库管/主管操作）
+    请求体: { "record_ids": [1, 2, 3], "reason": "物品丢失" }
+    """
+    data = request.get_json() or {}
+    record_ids = data.get('record_ids', [])
+    reason = data.get('reason', '')
+
+    if not record_ids:
+        return jsonify({'code': 400, 'msg': '请选择要报废的借出记录'}), 400
+
+    user = get_jwt_identity() or 'Unknown'
+    try:
+        result = TransService.scrap_borrow(record_ids, operator_name=user, reason=reason)
+        return jsonify({'code': 200, 'msg': f'已报废 {result["count"]} 条借出记录', 'data': result})
+    except ValueError as e:
+        return jsonify({'code': 400, 'msg': str(e)}), 400
+    except Exception as e:
+        traceback.print_exc()
+        return jsonify({'code': 500, 'msg': f'报废失败: {str(e)}'}), 500
+
+
 # --- 记录列表 ---
 @trans_bp.route('/records', methods=['GET'])
 @jwt_required()