test(client): 用例名统一为 should_<期望>_when_<条件>（155/155）

为什么：红线第 8 条门禁立即生效，要求 Flutter 测试命名合规；此前 155 条用例名是英文自然语言
或中文描述，合规数 0/155，属存量欠账，按"先补齐再上新功能"在本批处理。

- 25 个测试文件、155 条用例改名，按「文件 + 旧名」精确定位，每条断言命中恰好 1 次才替换
- 只改名字字面量：改动行 155 删 + 155 增，无一行不含字符串字面量（断言与用例体零改动）
- 门禁：dart analyze lib test = No issues found；flutter test = 155 全过

test/catalog/catalog_controller_test.dart

@@ -6,7 +6,7 @@ import 'package:nontonki/core/data/repositories/catalog_repository.dart';
 import 'package:nontonki/core/data/services/catalog_controller.dart';
 
 void main() {
-  test('空目录与加载失败可区分，重试后恢复', () async {
+  test('should_distinguish_empty_catalog_from_load_failure_when_retry_succeeds', () async {
     final repository = ScriptedCatalogRepository();
     final controller = CatalogController(repository);
 
@@ -30,7 +30,7 @@ void main() {
     expect(controller.sections.single.title, '热门推荐');
   });
 
-  test('详情按需加载：同一部短剧只请求一次', () async {
+  test('should_request_drama_detail_once_when_it_is_loaded_on_demand', () async {
     final repository = ScriptedCatalogRepository();
     final controller = CatalogController(repository);
     repository.feed = HomeFeed(
@@ -53,7 +53,7 @@ void main() {
     expect(controller.dramas.single.episodes, hasLength(2));
   });
 
-  test('播放票据：可播放写入地址，锁定集保持无地址', () async {
+  test('should_write_play_url_for_free_episode_and_keep_locked_episode_empty_when_ticket_is_issued', () async {
     final repository = ScriptedCatalogRepository();
     final controller = CatalogController(repository);
     repository.tickets['10'] = const PlayTicket(