refactor: 更新路由路径和导入路径，删除无用测试文件

- 将splash路由路径从'/'改为'/splash'以提高可读性
- 修正user_portrait服务中的导入路径
- 删除已不再需要的测试文件

lib/data/services/user_portrait.dart

@@ -1,4 +1,4 @@
-import 'package:deep_voice/core/utils/logger.dart';
+import '/core/utils/logger.dart';
 import 'package:get/get.dart';
 import 'package:user_portrait/user_portrait.dart';
 

lib/routes/app_routes.dart

@@ -1,6 +1,6 @@
 abstract class Routes {
   // 认证相关
-  static const splash = '/';
+  static const splash = '/splash';
   static const login = '/login';
   static const pairing = '/pairing';
 

local_plugins/user_portrait/test/user_portrait_method_channel_test.dart

@@ -1,27 +0,0 @@
-import 'package:flutter/services.dart';
-import 'package:flutter_test/flutter_test.dart';
-import 'package:user_portrait/user_portrait_method_channel.dart';
-
-void main() {
-  TestWidgetsFlutterBinding.ensureInitialized();
-
-  MethodChannelUserPortrait platform = MethodChannelUserPortrait();
-  const MethodChannel channel = MethodChannel('user_portrait');
-
-  setUp(() {
-    TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger.setMockMethodCallHandler(
-      channel,
-      (MethodCall methodCall) async {
-        return '42';
-      },
-    );
-  });
-
-  tearDown(() {
-    TestDefaultBinaryMessengerBinding.instance.defaultBinaryMessenger.setMockMethodCallHandler(channel, null);
-  });
-
-  test('getPlatformVersion', () async {
-    expect(await platform.getPlatformVersion(), '42');
-  });
-}

local_plugins/user_portrait/test/user_portrait_test.dart

@@ -1,29 +0,0 @@
-import 'package:flutter_test/flutter_test.dart';
-import 'package:user_portrait/user_portrait.dart';
-import 'package:user_portrait/user_portrait_platform_interface.dart';
-import 'package:user_portrait/user_portrait_method_channel.dart';
-import 'package:plugin_platform_interface/plugin_platform_interface.dart';
-
-class MockUserPortraitPlatform
-    with MockPlatformInterfaceMixin
-    implements UserPortraitPlatform {
-
-  @override
-  Future<String?> getPlatformVersion() => Future.value('42');
-}
-
-void main() {
-  final UserPortraitPlatform initialPlatform = UserPortraitPlatform.instance;
-
-  test('$MethodChannelUserPortrait is the default instance', () {
-    expect(initialPlatform, isInstanceOf<MethodChannelUserPortrait>());
-  });
-
-  test('getPlatformVersion', () async {
-    UserPortrait userPortraitPlugin = UserPortrait();
-    MockUserPortraitPlatform fakePlatform = MockUserPortraitPlatform();
-    UserPortraitPlatform.instance = fakePlatform;
-
-    expect(await userPortraitPlugin.getPlatformVersion(), '42');
-  });
-}