fix: CardService에서 존재하지 않는 User 관계 제거 (department, position)

app/Services/CardService.php

@@ -17,7 +17,7 @@ public function index(array $params): LengthAwarePaginator
 
         $query = Card::query()
             ->where('tenant_id', $tenantId)
-            ->with(['assignedUser:id,name,email', 'assignedUser.department', 'assignedUser.position']);
+            ->with(['assignedUser:id,name,email']);
 
         // 검색 필터
         if (!empty($params['search'])) {