fix(WEB): ItemListClient 검색 변경 핸들러 연결

- handleSearchChange 핸들러 추가
- onSearchChange prop 연결로 검색 기능 정상화

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

src/components/items/ItemListClient.tsx

@@ -127,6 +127,11 @@ export default function ItemListClient() {
     setSelectedType(value);
   };
 
+  // 검색 변경 핸들러
+  const handleSearchChange = (value: string) => {
+    setSearchTerm(value);
+  };
+
   // 페이지 변경 핸들러
   const handlePageChange = (page: number) => {
     search({
@@ -614,6 +619,7 @@ export default function ItemListClient() {
         config={config}
         initialData={items}
         onTabChange={handleTypeChange}
+        onSearchChange={handleSearchChange}
         externalPagination={{
           currentPage: pagination.currentPage,
           totalPages: pagination.totalPages,