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/core/android_picture_in_picture_test.dart

@@ -0,0 +1,132 @@
+import 'package:flutter/foundation.dart';
+import 'package:flutter/services.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:nontonki/core/data/services/android_picture_in_picture.dart';
+
+void main() {
+  TestWidgetsFlutterBinding.ensureInitialized();
+
+  const channel = MethodChannel('test/pip_channel');
+  final messenger =
+      TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger;
+
+  AndroidPictureInPicture pip() => AndroidPictureInPicture(channel: channel);
+
+  /// Simulates a native call arriving on the channel.
+  Future<void> sendToDart(String method, Object? arguments) => messenger
+      .handlePlatformMessage(
+        channel.name,
+        const StandardMethodCodec().encodeMethodCall(
+          MethodCall(method, arguments),
+        ),
+        (_) {},
+      );
+
+  tearDown(() {
+    debugDefaultTargetPlatformOverride = null;
+    channel.setMethodCallHandler(null);
+  });
+
+  group('platform support', () {
+    test('android is the only supported target', () {
+      debugDefaultTargetPlatformOverride = TargetPlatform.android;
+      expect(pip().isPlatformSupported, isTrue);
+
+      for (final platform in <TargetPlatform>[
+        TargetPlatform.iOS,
+        TargetPlatform.macOS,
+        TargetPlatform.linux,
+        TargetPlatform.windows,
+        TargetPlatform.fuchsia,
+      ]) {
+        debugDefaultTargetPlatformOverride = platform;
+        expect(
+          pip().isPlatformSupported,
+          isFalse,
+          reason: '$platform must not claim picture in picture support',
+        );
+      }
+    });
+  });
+
+  group('enter', () {
+    test('is refused without touching the channel off android', () async {
+      debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
+      final calls = <MethodCall>[];
+      messenger.setMockMethodCallHandler(channel, (call) async {
+        calls.add(call);
+        return true;
+      });
+      addTearDown(() => messenger.setMockMethodCallHandler(channel, null));
+
+      expect(await pip().enter(), isFalse);
+      expect(calls, isEmpty);
+    });
+
+    test('a missing native answer counts as a refusal', () async {
+      debugDefaultTargetPlatformOverride = TargetPlatform.android;
+      messenger.setMockMethodCallHandler(channel, (call) async => null);
+      addTearDown(() => messenger.setMockMethodCallHandler(channel, null));
+
+      expect(await pip().enter(), isFalse);
+    });
+
+    test('a native success is reported as entered', () async {
+      debugDefaultTargetPlatformOverride = TargetPlatform.android;
+      final calls = <MethodCall>[];
+      messenger.setMockMethodCallHandler(channel, (call) async {
+        calls.add(call);
+        return true;
+      });
+      addTearDown(() => messenger.setMockMethodCallHandler(channel, null));
+
+      expect(await pip().enter(), isTrue);
+      expect(calls.single.method, 'enter');
+      expect(calls.single.arguments, isNull);
+    });
+  });
+
+  group('state listener', () {
+    test('pip state changes reach the listener in order', () async {
+      final received = <bool>[];
+      pip().setStateListener(received.add);
+
+      await sendToDart('onPipChanged', true);
+      await sendToDart('onPipChanged', false);
+
+      expect(received, [true, false]);
+    });
+
+    test('only a literal true is read as enabled', () async {
+      final received = <bool>[];
+      pip().setStateListener(received.add);
+
+      await sendToDart('onPipChanged', null);
+      await sendToDart('onPipChanged', 'yes');
+      await sendToDart('onPipChanged', 1);
+
+      expect(received, [false, false, false]);
+    });
+
+    test('unrelated native methods are ignored', () async {
+      final received = <bool>[];
+      pip().setStateListener(received.add);
+
+      await sendToDart('somethingElse', true);
+      await sendToDart('onPipChanged', true);
+
+      expect(received, [true]);
+    });
+
+    test('clearing the listener silences later callbacks', () async {
+      final received = <bool>[];
+      final observer = pip()..setStateListener(received.add);
+      await sendToDart('onPipChanged', true);
+
+      observer.setStateListener(null);
+      await sendToDart('onPipChanged', true);
+
+      expect(received, [true]);
+    });
+  });
+}