fix: 修复审批消息推送问题

问题1：BusinessTripService 数据格式兼容性
- 后端期望对象数组 [{id:1, name:'...'}]，前端传纯 ID 数组 [1,2,3]
- 修复：兼容两种格式，自动提取 id

问题2：ApprovalService 没有消息推送
- 添加 FeishuNotificationService 集成
- approve() 方法：节点完成后通知下一节点审批人，流程完成后通知申请人
- reject() 方法：审批拒绝时通知申请人

问题3：修复重复类定义导致的语法错误

相关文件：
- backend/app/service/BusinessTripService.php
- backend/app/service/ApprovalService.php

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

backend/app/service/ApprovalService.php

@@ -13,6 +13,7 @@ use Illuminate\Database\Connection;
 class ApprovalService
 {
     private Connection $db;
+    private ?FeishuNotificationService $notificationService = null;
 
     public function __construct()
     {
@@ -96,6 +97,9 @@ class ApprovalService
                     // 没有下一节点，审批完成
                     $order->status = ApprovalOrder::STATUS_APPROVED;
                     $order->current_nodes = [];
+
+                    // 通知申请人审批通过
+                    $this->notifyApplicant($order, 'approve');
                 } else {
                     // 检查第一个下一节点
                     $firstNextNode = $nextNodes[0] ?? null;
@@ -103,9 +107,15 @@ class ApprovalService
                         // 下一个是抄送节点，跳过并完成流程
                         $order->status = ApprovalOrder::STATUS_APPROVED;
                         $order->current_nodes = [];
+
+                        // 通知申请人审批通过
+                        $this->notifyApplicant($order, 'approve');
                     } else {
                         // 下一个是审批节点，移动到该节点
                         $order->current_nodes = collect($nextNodes)->pluck('id')->toArray();
+
+                        // 通知下一节点的审批人
+                        $this->notifyNextApprovers($order, $nextNodes);
                     }
                 }
 
@@ -146,6 +156,9 @@ class ApprovalService
             $order->current_nodes = [];
             $order->save();
 
+            // 通知申请人审批被拒绝
+            $this->notifyApplicant($order, 'reject', $comment);
+
             return $order->fresh(['flow', 'applicant', 'records']);
         });
     }
@@ -381,4 +394,138 @@ class ApprovalService
 
         return $result;
     }
+
+    /**
+     * 通知申请人
+     */
+    private function notifyApplicant(ApprovalOrder $order, string $action, ?string $comment = null): void
+    {
+        try {
+            if (!$this->notificationService) {
+                $this->notificationService = new FeishuNotificationService();
+            }
+
+            $applicant = User::find($order->applicant_id);
+            if (!$applicant) {
+                error_log("❌ notifyApplicant: 申请人不存在, applicant_id={$order->applicant_id}");
+                return;
+            }
+
+            // 根据业务类型获取详情链接
+            $detailUrl = $this->getDetailUrl($order);
+
+            // 构建消息内容
+            $title = $action === 'approve' ? '您的申请已通过' : '您的申请已被拒绝';
+            $content = "**申请标题**: {$order->title}\n";
+            $content .= "**申请类型**: {$this->getBusinessTypeName($order->business_type)}\n";
+
+            if ($comment) {
+                $content .= "**审批意见**: {$comment}\n";
+            }
+
+            error_log("🔔 通知申请人: applicant_id={$applicant->id}, action={$action}");
+
+            $this->notificationService->setAppByUser($applicant->id)
+                ->sendSystemNotification([
+                    'user_ids' => [$applicant->id],
+                    'title' => $title,
+                    'content' => $content,
+                    'url' => $detailUrl,
+                ]);
+        } catch (\Exception $e) {
+            error_log('❌ notifyApplicant 失败: ' . $e->getMessage());
+        }
+    }
+
+    /**
+     * 通知下一节点的审批人
+     */
+    private function notifyNextApprovers(ApprovalOrder $order, array $nextNodes): void
+    {
+        try {
+            if (!$this->notificationService) {
+                $this->notificationService = new FeishuNotificationService();
+            }
+
+            // 从 form_data 获取审批人列表
+            $formData = $order->form_data ?? [];
+            $approvers = $formData['approvers'] ?? [];
+
+            // 兼容两种格式
+            if (!empty($approvers) && is_array($approvers[0] ?? null) && isset($approvers[0]['id'])) {
+                $approverIds = array_column($approvers, 'id');
+            } else {
+                $approverIds = $approvers;
+            }
+
+            if (empty($approverIds)) {
+                error_log("⚠️ notifyNextApprovers: 没有找到审批人, order_id={$order->id}");
+                return;
+            }
+
+            // 获取详情链接
+            $detailUrl = $this->getDetailUrl($order);
+
+            // 业务类型名称
+            $businessTypeName = $this->getBusinessTypeName($order->business_type);
+
+            error_log("🔔 通知下一节点审批人: order_id={$order->id}, approverIds=" . json_encode($approverIds));
+
+            // 为每个审批人发送通知
+            foreach ($approverIds as $approverId) {
+                try {
+                    $this->notificationService->setAppByUser($approverId)
+                        ->sendApprovalNotification([
+                            'user_id' => $approverId,
+                            'title' => '新的审批待办',
+                            'applicant' => $order->applicant->name,
+                            'type' => $businessTypeName,
+                            'content' => "**申请标题**: {$order->title}\n**申请人**: {$order->applicant->name}",
+                            'url' => $detailUrl,
+                        ]);
+                    error_log("✅ 审批人通知成功: approver_id={$approverId}");
+                } catch (\Exception $e) {
+                    error_log("❌ 发送审批通知失败: approver_id={$approverId}, error=" . $e->getMessage());
+                }
+            }
+        } catch (\Exception $e) {
+            error_log('❌ notifyNextApprovers 失败: ' . $e->getMessage());
+        }
+    }
+
+    /**
+     * 获取详情链接
+     */
+    private function getDetailUrl(ApprovalOrder $order): string
+    {
+        $baseUrl = 'https://xsm.dev.hnxinyouhe.com';
+
+        switch ($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}";
+        }
+    }
+
+    /**
+     * 获取业务类型名称
+     */
+    private function getBusinessTypeName(string $businessType): string
+    {
+        $typeNames = [
+            'business_trip' => '出差申请',
+            'expense' => '费用报销',
+            'leave' => '请假申请',
+            'purchase' => '采购申请',
+        ];
+
+        return $typeNames[$businessType] ?? $businessType;
+    }
 }