fix: [재공품] 수주 수정 시 item_id 미해석 + 작업자화면 BD코드 fallback

- OrderService::update()에 item_code→item_id 해석 로직 추가 (store()에만 있던 것)
- WorkOrderService: sourceOrderItem에 item_code 필드 포함 (BD코드 fallback용)

app/Services/WorkOrderService.php

@@ -63,7 +63,7 @@ public function index(array $params)
                 'process:id,process_name,process_code,department,options',
                 'items:id,work_order_id,item_id,item_name,specification,quantity,unit,status,options,sort_order,source_order_item_id',
                 'items.item:id,code',
-                'items.sourceOrderItem:id,order_node_id,floor_code,symbol_code',
+                'items.sourceOrderItem:id,order_node_id,floor_code,symbol_code,item_code',
                 'items.sourceOrderItem.node:id,name,code',
                 'items.materialInputs:id,work_order_id,work_order_item_id,stock_lot_id,item_id,qty,input_by,input_at',
                 'items.materialInputs.stockLot:id,lot_no',
@@ -347,7 +347,7 @@ public function show(int $id)
                 'process:id,process_name,process_code,work_steps,department,options',
                 'process.steps' => fn ($q) => $q->where('is_active', true)->orderBy('sort_order'),
                 'items.item:id,code',
-                'items.sourceOrderItem:id,order_node_id,floor_code,symbol_code',
+                'items.sourceOrderItem:id,order_node_id,floor_code,symbol_code,item_code',
                 'items.sourceOrderItem.node:id,name,code',
                 'items.materialInputs:id,work_order_id,work_order_item_id,stock_lot_id,item_id,qty,input_by,input_at',
                 'items.materialInputs.stockLot:id,lot_no',