feat: 审批功能优化和拒绝原因弹窗

后端改动：
- ApprovalService: 添加调试日志，简化详情页 URL 生成逻辑
- BusinessTripService: 优化出差审批详情展示

前端改动：
- approval/detail: 审批详情页优化，支持查看完整审批流程
- approval/reject: 新增拒绝原因弹窗组件
- business-trip/detail: 出差详情页增强，展示审批状态和操作

功能特性：
- 审批详情页显示完整审批流程和记录
- 拒绝操作支持填写拒绝原因
- 出差申请详情页优化展示

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/app/service/ApprovalService.php

@@ -72,9 +72,12 @@ class ApprovalService
             }
 
             $currentNodeIds = $order->current_nodes ?? [];
+            error_log("🔍 当前节点 IDs: " . json_encode($currentNodeIds));
+
             $currentNode = ApprovalNode::whereIn('id', $currentNodeIds)->first();
 
             if (!$currentNode) {
+                error_log("❌ 未找到节点，IDs: " . json_encode($currentNodeIds));
                 throw new \Exception('当前节点不存在');
             }
 
@@ -501,18 +504,8 @@ class ApprovalService
     {
         $baseUrl = 'https://xsm.dev.hnxinyouhe.com';
 
-        switch ($order->business_type) {
-            case 'business_trip':
-                return "{$baseUrl}/business-trip/detail/{$order->business_id}";
-            case 'expense':
-                return "{$baseUrl}/expense/detail/{$order->business_id}";
-            case 'leave':
-                return "{$baseUrl}/leave/detail/{$order->business_id}";
-            case 'purchase':
-                return "{$baseUrl}/purchase/detail/{$order->business_id}";
-            default:
-                return "{$baseUrl}/approval/detail/{$order->id}";
-        }
+        // 统一使用审批详情页，不再跳转到具体业务模块的详情页
+        return "{$baseUrl}/approval/detail/{$order->id}";
     }
 
     /**