fix:partner-activity 뷰에서 tenant 타입 처리 누락 수정

- type이 'tenant'인 경우 $item['prospect']가 없어서 500 에러 발생
- $prospect->company_name 대신 $item['company_name'] 사용
- $tenant 변수도 추가하여 타입별 처리 가능하도록 수정

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

resources/views/sales/dashboard/partials/partner-activity.blade.php

@@ -81,7 +81,8 @@
             <div class="divide-y divide-gray-100">
                 @foreach($managerOnlyProspects as $item)
                     @php
-                        $prospect = $item['prospect'];
+                        $prospect = $item['prospect'] ?? null;
+                        $tenant = $item['tenant'] ?? null;
                         $management = $item['management'];
                         $registeredBy = $item['registeredBy'];
                         $progress = $item['progress'];
@@ -94,8 +95,8 @@
                         <div class="flex items-center justify-between mb-3">
                             <div class="flex items-center gap-3">
                                 <div>
-                                    <p class="font-bold text-gray-900">{{ $prospect->company_name }}</p>
-                                    <p class="text-xs text-gray-500">{{ $prospect->business_number ?? '-' }}</p>
+                                    <p class="font-bold text-gray-900">{{ $item['company_name'] }}</p>
+                                    <p class="text-xs text-gray-500">{{ $item['business_number'] ?? '-' }}</p>
                                 </div>
                                 <span class="px-2 py-0.5 text-xs font-medium rounded-full bg-green-100 text-green-700">
                                     매니저만 진행