feat(flutter): 优化浅色开屏与原生过渡

lib/pages/splash/splash_page.dart

@@ -7,8 +7,7 @@ import 'package:flutter/services.dart';
 
 import '../../core/theme/app_colors.dart';
 
-const Color _splashBackground = Color(0xFF100C0A);
-const Color _markGlow = Color(0x40FF7A1A);
+const Color _markGlow = Color(0x33FF7A1A);
 const double _markSize = 112;
 const double _markRadius = 24;
 const double _logoGlowSize = 144;
@@ -18,7 +17,7 @@ const double _loaderStroke = 2;
 const String _markAsset = 'assets/icon/splash_mark.png';
 const Duration _introDuration = Duration(milliseconds: 1200);
 
-/// 品牌开屏：深暖底上依次呈现水果标记、FruitShorts 与中文标语。
+/// 品牌开屏：浅暖底上依次呈现水果标记、FruitShorts 与中文标语。
 class SplashPage extends StatefulWidget {
   const SplashPage({super.key});
 
@@ -75,10 +74,10 @@ class _SplashPageState extends State<SplashPage>
   @override
   Widget build(BuildContext context) {
     return AnnotatedRegion<SystemUiOverlayStyle>(
-      value: SystemUiOverlayStyle.light,
+      value: SystemUiOverlayStyle.dark,
       child: ColoredBox(
         key: const Key('splash-screen'),
-        color: _splashBackground,
+        color: AppColors.ink,
         child: Stack(
           fit: StackFit.expand,
           children: [
@@ -178,7 +177,7 @@ class _SplashPageState extends State<SplashPage>
           'FruitShorts',
           key: Key('splash-brand'),
           style: TextStyle(
-            color: Colors.white,
+            color: AppColors.onSurface,
             fontSize: 28,
             fontWeight: FontWeight.w900,
             fontFamily: 'Outfit',
@@ -202,7 +201,7 @@ class _SplashPageState extends State<SplashPage>
           '水果短剧',
           key: Key('splash-tagline'),
           style: TextStyle(
-            color: Colors.white70,
+            color: AppColors.muted,
             fontSize: 13,
             letterSpacing: 4,
           ),