feat(app): 搜索改为调用后端并渲染卡片结果

lib/core/data/remote/catalog_api.dart

@@ -1,5 +1,6 @@
 import '../models/drama.dart';
 import '../models/home_feed.dart';
+import '../models/search_result.dart';
 import 'api_client.dart';
 
 /// 客户端目录接口，对应后端 `/app/**`。
@@ -16,6 +17,23 @@ class CatalogApi {
     return HomeFeed.fromJson(_asMap(await _client.get('/app/discover/feed')));
   }
 
+  /// 搜索已上线短剧：按标题/简介模糊匹配，分页返回卡片列表。
+  Future<SearchResult> search(
+    String keyword, {
+    int pageIndex = 1,
+    int pageSize = 20,
+  }) async {
+    final data = await _client.get(
+      '/app/search',
+      query: {
+        'keyword': keyword,
+        'pageIndex': '$pageIndex',
+        'pageSize': '$pageSize',
+      },
+    );
+    return SearchResult.fromJson(_asMap(data));
+  }
+
   Future<Drama> dramaDetail(String dramaId) async {
     return Drama.fromDetailJson(
       _asMap(await _client.get('/app/dramas/$dramaId')),