fix(approve): 修复审批流程为空时的异常处理

liyong

2026-04-30 c2ad2126d6f8423e0a5e6e20bbb91ef6bb1cffc0

 src/main/java/com/ruoyi/purchase/service/IPurchaseLedgerService.java

@@ -43,4 +43,6 @@
    String getPurchaseNo();

    AjaxResult importData(MultipartFile file);

    PurchaseLedgerDto getPurchaseByCode(PurchaseLedgerDto purchaseLedgerDto);
}