feat(auth): 登录页改为 ymb 品牌并支持后台配置背景图

test/widget_test.dart

@@ -138,7 +138,7 @@ void main() {
     await tester.tap(find.byKey(const Key('tab-mine')));
     await tester.pumpAndSettle();
     expect(find.text('Vicky sheng'), findsOneWidget);
-    expect(find.text('FruitShorts VIP'), findsOneWidget);
+    expect(find.text('VIP'), findsOneWidget);
     expect(find.byKey(const Key('mine-language')), findsOneWidget);
     expect(find.byKey(const Key('mine-wallet')), findsOneWidget);
 
@@ -265,7 +265,7 @@ void main() {
     await tester.tap(find.byKey(const Key('player-rail-share')));
     await tester.pumpAndSettle();
     expect(sharedText, contains('City Lights & Velvet Nights'));
-    expect(sharedText, contains('FruitShorts'));
+    expect(sharedText, contains('ymb'));
     expect(tester.takeException(), isNull);
   });