refactor: UniversalListPage externalIsLoading 지원 및 스켈레톤 개선

- UniversalListPage에 externalIsLoading prop 추가
- CardTransactionDetailClient DevFill 자동입력 기능 추가
- 여러 컴포넌트 로딩 상태 처리 개선
- skeleton 컴포넌트 확장

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

src/components/items/ItemListClient.tsx

@@ -18,7 +18,6 @@ import { Checkbox } from '@/components/ui/checkbox';
 import { TableRow, TableCell } from '@/components/ui/table';
 import { DeleteConfirmDialog } from '@/components/ui/confirm-dialog';
 import { Search, Plus, Edit, Trash2, Package } from 'lucide-react';
-import { TableLoadingSpinner } from '@/components/ui/loading-spinner';
 import { useItemList } from '@/hooks/useItemList';
 import { handleApiError } from '@/lib/api/error-handler';
 import { isNextRedirectError } from '@/lib/utils/redirect-error';
@@ -122,11 +121,6 @@ export default function ItemListClient() {
     });
   }, [debouncedSearchTerm, selectedType, search]);
 
-  // 로딩 상태
-  if (isLoading) {
-    return <TableLoadingSpinner text="품목 목록을 불러오는 중..." />;
-  }
-
   // 유형 변경 핸들러
   const handleTypeChange = (value: string) => {
     setSelectedType(value);
@@ -491,6 +485,7 @@ export default function ItemListClient() {
           itemsPerPage: pagination.perPage,
           onPageChange: handlePageChange,
         }}
+        externalIsLoading={isLoading}
       />
 
       {/* 개별 삭제 확인 다이얼로그 */}