feat(ui): 更新品牌启动页与选集交互

lib/core/theme/app_theme.dart

@@ -4,10 +4,10 @@ import 'package:flutter/material.dart';
 
 import 'app_colors.dart';
 
-/// App-wide light and dark themes built from the approved Klein Blue palette.
+/// Light paper and warm-cocoa themes for the Indonesia evening palette.
 abstract final class AppTheme {
-  static const _lightBackground = Color(0xFFF8F7FC);
-  static const _darkBackground = Color(0xFF101019);
+  static const _lightBackground = Color(0xFFFFF6F1);
+  static const _darkBackground = AppColors.ink;
 
   /// Light theme for system light mode.
   static ThemeData light() => _build(
@@ -40,7 +40,7 @@ abstract final class AppTheme {
             secondaryContainer: AppColors.bluePressed,
             onSecondaryContainer: AppColors.onPrimary,
             surface: _darkBackground,
-            onSurface: Colors.white,
+            onSurface: AppColors.cream,
             outline: AppColors.outlineDark,
             outlineVariant: AppColors.outlineVariantDark,
             surfaceTint: AppColors.blueSoft,