fix: 添加订单状态检查和友好错误提示

- 检测订单已完成状态，返回友好提示
- 添加infoCard方法显示中性提示
- 优化自审批错误处理

backend/app/service/ApprovalService.php

@@ -553,10 +553,23 @@ class ApprovalService
         $currentNodeIds = $order->current_nodes ?? [];
         error_log("🔄 自审批自动通过 - 当前节点: " . json_encode($currentNodeIds));
 
+        // 检查订单是否已经结束
+        if (empty($currentNodeIds)) {
+            error_log("❌ 自审批：订单已完成，current_nodes为空");
+            if ($order->status === ApprovalOrder::STATUS_APPROVED) {
+                throw new \Exception('该申请已通过，无需重复操作');
+            } else if ($order->status === ApprovalOrder::STATUS_REJECTED) {
+                throw new \Exception('该申请已被拒绝');
+            } else if ($order->status === ApprovalOrder::STATUS_CANCELLED) {
+                throw new \Exception('该申请已被撤销');
+            }
+            throw new \Exception('该申请已完成，无法重复操作');
+        }
+
         $currentNode = ApprovalNode::whereIn('id', $currentNodeIds)->first();
 
         if (!$currentNode) {
-            error_log("❌ 自审批：当前节点不存在");
+            error_log("❌ 自审批：当前节点不存在，IDs: " . json_encode($currentNodeIds));
             throw new \Exception('当前节点不存在');
         }