fix: [approvals] 결재자 검색 API 응답 필드 수정

- department_name → department 필드명 변경 (프론트엔드 호환)
- tenant_user_profiles 조인으로 position(직급) 데이터 추가
- 부서명 검색 지원 추가

app/Http/Controllers/Api/Admin/TenantUserApiController.php

@@ -23,18 +23,16 @@ public function search(Request $request): JsonResponse
                     ->where('user_tenants.tenant_id', $tenantId)
                     ->where('user_tenants.is_active', true);
             })
-            ->leftJoin('departments', function ($join) {
-                $join->on('departments.id', '=', DB::raw('(
-                    SELECT du.department_id FROM department_user du
-                    WHERE du.user_id = users.id AND du.is_primary = 1
-                    LIMIT 1
-                )'));
+            ->leftJoin('tenant_user_profiles as tp', function ($join) use ($tenantId) {
+                $join->on('tp.user_id', '=', 'users.id')
+                    ->where('tp.tenant_id', $tenantId);
             })
+            ->leftJoin('departments', 'departments.id', '=', 'tp.department_id')
             ->whereNull('users.deleted_at')
             ->when($query, function ($q) use ($query) {
                 $q->where(function ($sub) use ($query) {
                     $sub->where('users.name', 'like', "%{$query}%")
-                        ->orWhere('users.email', 'like', "%{$query}%");
+                        ->orWhere('departments.name', 'like', "%{$query}%");
                 });
             })
             ->orderBy('users.name')
@@ -42,7 +40,8 @@ public function search(Request $request): JsonResponse
             ->select([
                 'users.id',
                 'users.name',
-                'departments.name as department_name',
+                'departments.name as department',
+                'tp.position_key as position',
             ])
             ->get();