chore(client): 归档原型阶段新增文件（配置、主题、模型与测试）

为什么：上一批归档只覆盖了「已跟踪文件的修改」，原型阶段新增的文件（app_config、theme、
home_feed/play_ticket 模型、catalog_api、测试目录等）还是未入库状态 —— 而已入库的代码会 import 它们，
留在工作区会导致 HEAD 处的代码编译不过。一并归档，让 HEAD 自洽。

纯归档，无行为改动。

test/discover/cover_carousel_test.dart

@@ -0,0 +1,51 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:nontonki/pages/discover/widgets/cover_carousel.dart';
+
+void main() {
+  TestWidgetsFlutterBinding.ensureInitialized();
+
+  testWidgets('the cube turns and keeps the title on the poster', (tester) async {
+    await tester.pumpWidget(
+      MaterialApp(
+        home: Scaffold(
+          body: CoverCarousel(
+            items: [
+              for (final title in ['The Signal', 'City Lights', 'Vengeance'])
+                CoverItem(
+                  title: title,
+                  subtitle: 'Mock',
+                  image: '/files/poster.png',
+                  onOpen: _noop,
+                ),
+            ],
+          ),
+        ),
+      ),
+    );
+    await tester.pump();
+
+    expect(find.text('The Signal'), findsOneWidget);
+    expect(find.text('Mock'), findsOneWidget);
+
+    final box = tester.getRect(find.byType(CoverCarousel));
+    final gesture = await tester.startGesture(Offset(box.right - 40, box.center.dy));
+    await gesture.moveBy(const Offset(-500, 0));
+    await tester.pump();
+
+    final turned = tester.widgetList<Transform>(find.byType(Transform)).any(
+      (transform) => (transform.transform.entry(0, 0) - 1).abs() > 0.15,
+    );
+    expect(turned, isTrue);
+
+    await gesture.moveBy(const Offset(-200, 0));
+    await gesture.up();
+    await tester.pump();
+    await tester.pump(const Duration(milliseconds: 450));
+
+    expect(find.text('City Lights'), findsOneWidget);
+    expect(tester.takeException(), isNull);
+  });
+}
+
+void _noop() {}