refactor(theme): 迁移主题感知颜色至 ThemeExtension

- 创建 AppThemeColors ThemeExtension 类，统一管理主题感知颜色（涨跌色、卡片背景、渐变等）
- 从 AppColorScheme 移除主题感知辅助函数，仅保留静态颜色常量
- 在 AppTheme 中注册 ThemeExtension，支持深色/浅色主题工厂
- 重构所有 UI 组件使用 context.appColors 访问主题颜色，替代硬编码的 AppColorScheme 方法调用
- 移除组件中重复的 isDark 判断逻辑，简化颜色获取方式
- 保持向后兼容性，所有现有功能不变

flutter_monisuo/lib/ui/pages/asset/components/account_tab_switcher.dart

@@ -1,5 +1,6 @@
 import 'package:flutter/material.dart';
 import '../../../../core/theme/app_theme.dart';
+import '../../../../core/theme/app_theme_extension.dart';
 import '../../../../core/theme/app_spacing.dart';
 
 /// 账户标签切换器 — .pen node UE6xC
@@ -19,14 +20,11 @@ class AccountTabSwitcher extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    final colorScheme = Theme.of(context).colorScheme;
-    final isDark = Theme.of(context).brightness == Brightness.dark;
-
     return Container(
       height: 40,
       padding: const EdgeInsets.all(3),
       decoration: BoxDecoration(
-        color: isDark ? colorScheme.surfaceContainerHighest : colorScheme.surfaceContainerHigh,
+        color: context.appColors.surfaceCardHigh,
         borderRadius: BorderRadius.circular(AppRadius.md),
       ),
       child: Row(
@@ -36,14 +34,12 @@ class AccountTabSwitcher extends StatelessWidget {
             label: '资金账户',
             isSelected: selectedIndex == 0,
             onTap: () => onChanged(0),
-            isDark: isDark,
           ),
           _buildTab(
             context: context,
             label: '交易账户',
             isSelected: selectedIndex == 1,
             onTap: () => onChanged(1),
-            isDark: isDark,
           ),
         ],
       ),
@@ -55,10 +51,7 @@ class AccountTabSwitcher extends StatelessWidget {
     required String label,
     required bool isSelected,
     required VoidCallback onTap,
-    required bool isDark,
   }) {
-    final colorScheme = Theme.of(context).colorScheme;
-
     return Expanded(
       child: GestureDetector(
         onTap: onTap,
@@ -66,13 +59,13 @@ class AccountTabSwitcher extends StatelessWidget {
           duration: const Duration(milliseconds: 200),
           decoration: BoxDecoration(
             color: isSelected
-                ? colorScheme.surface
+                ? context.colors.surface
                 : const Color(0x00000000),
             borderRadius: BorderRadius.circular(AppRadius.sm),
             boxShadow: isSelected
                 ? [
                     BoxShadow(
-                      color: colorScheme.shadow.withValues(alpha: 0.05),
+                      color: context.colors.shadow.withValues(alpha: 0.05),
                       blurRadius: 3,
                       offset: const Offset(0, 1),
                     ),
@@ -86,7 +79,7 @@ class AccountTabSwitcher extends StatelessWidget {
                 ? AppTextStyles.headlineMedium(context)
                 : AppTextStyles.headlineMedium(context).copyWith(
                     fontWeight: FontWeight.w500,
-                    color: colorScheme.onSurfaceVariant,
+                    color: context.colors.onSurfaceVariant,
                   ),
           ),
         ),

flutter_monisuo/lib/ui/pages/asset/components/action_buttons_row.dart

@@ -2,6 +2,7 @@ import 'package:flutter/material.dart';
 import 'package:lucide_icons_flutter/lucide_icons.dart';
 import '../../../../core/theme/app_spacing.dart';
 import '../../../../core/theme/app_theme.dart';
+import '../../../../core/theme/app_theme_extension.dart';
 
 /// 操作按钮行 — .pen node pIpHe
 /// gap: 12, three buttons evenly distributed
@@ -22,10 +23,8 @@ class ActionButtonsRow extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    final colorScheme = Theme.of(context).colorScheme;
-    final isDark = Theme.of(context).brightness == Brightness.dark;
-    final accentColor = isDark ? colorScheme.secondary : colorScheme.primary;
-    final bgColor = isDark ? colorScheme.surfaceContainerHighest : colorScheme.surfaceContainerHigh;
+    final accentColor = context.appColors.accentPrimary;
+    final bgColor = context.appColors.surfaceCardHigh;
 
     return Row(
       children: [

flutter_monisuo/lib/ui/pages/asset/components/asset_dialogs.dart

@@ -4,6 +4,7 @@ import 'package:shadcn_ui/shadcn_ui.dart';
 import 'package:lucide_icons_flutter/lucide_icons.dart';
 import 'package:provider/provider.dart';
 import '../../../../core/theme/app_theme.dart';
+import '../../../../core/theme/app_theme_extension.dart';
 import '../../../../core/theme/app_color_scheme.dart';
 import '../../../../core/theme/app_spacing.dart';
 import '../../../../core/utils/toast_utils.dart';
@@ -246,7 +247,6 @@ void showDepositResultDialog(BuildContext context, Map<String, dynamic> data) {
   final walletAddress = data['walletAddress'] as String? ?? '';
   final walletNetwork = data['walletNetwork'] as String? ?? 'TRC20';
   final colorScheme = Theme.of(context).colorScheme;
-  final isDark = Theme.of(context).brightness == Brightness.dark;
 
   showShadDialog(
     context: context,
@@ -263,7 +263,7 @@ void showDepositResultDialog(BuildContext context, Map<String, dynamic> data) {
               children: [
                 NeonIcon(
                   icon: Icons.check_circle,
-                  color: AppColorScheme.getUpColor(isDark),
+                  color: context.appColors.up,
                   size: 24,
                 ),
                 const SizedBox(width: AppSpacing.sm),
@@ -361,7 +361,6 @@ void showWithdrawDialog(BuildContext context, String? balance) {
   final contactController = TextEditingController();
   final formKey = GlobalKey<ShadFormState>();
   final colorScheme = Theme.of(context).colorScheme;
-  final isDark = Theme.of(context).brightness == Brightness.dark;
 
   showShadDialog(
     context: context,
@@ -412,10 +411,10 @@ void showWithdrawDialog(BuildContext context, String? balance) {
                     vertical: AppSpacing.sm,
                   ),
                   decoration: BoxDecoration(
-                    color: AppColorScheme.getUpBackgroundColor(isDark),
+                    color: context.appColors.upBackground,
                     borderRadius: BorderRadius.circular(AppRadius.full),
                     border: Border.all(
-                      color: AppColorScheme.getUpColor(isDark).withValues(alpha: 0.2),
+                      color: context.appColors.up.withValues(alpha: 0.2),
                     ),
                   ),
                   child: Row(
@@ -431,7 +430,7 @@ void showWithdrawDialog(BuildContext context, String? balance) {
                         '$balance USDT',
                         style: AppTextStyles.labelLarge(context).copyWith(
                           fontWeight: FontWeight.bold,
-                          color: AppColorScheme.getUpColor(isDark),
+                          color: context.appColors.up,
                         ),
                       ),
                     ],

flutter_monisuo/lib/ui/pages/asset/components/balance_card.dart

@@ -1,6 +1,6 @@
 import 'package:flutter/material.dart';
 import '../../../../core/theme/app_theme.dart';
-import '../../../../core/theme/app_color_scheme.dart';
+import '../../../../core/theme/app_theme_extension.dart';
 import '../../../../core/theme/app_spacing.dart';
 import '../../../../providers/asset_provider.dart';
 import '../../../components/glass_panel.dart';
@@ -22,9 +22,6 @@ class BalanceCard extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    final colorScheme = Theme.of(context).colorScheme;
-    final isDark = Theme.of(context).brightness == Brightness.dark;
-
     final displayBalance = activeTab == 0
         ? (provider.fundAccount?.balance ?? provider.overview?.fundBalance ?? '0.00')
         : _calculateTradeTotal();
@@ -38,7 +35,7 @@ class BalanceCard extends StatelessWidget {
           Text(
             'USDT 余额',
             style: AppTextStyles.bodyMedium(context).copyWith(
-              color: colorScheme.onSurfaceVariant,
+              color: context.colors.onSurfaceVariant,
               fontWeight: FontWeight.w400,
             ),
           ),
@@ -51,7 +48,7 @@ class BalanceCard extends StatelessWidget {
           Text(
             '\u2248 \$${_formatBalance(displayBalance)} USD',
             style: AppTextStyles.bodyMedium(context).copyWith(
-              color: isDark ? AppColorScheme.darkOnSurfaceMuted : colorScheme.onSurfaceVariant,
+              color: context.appColors.onSurfaceMuted,
               fontWeight: FontWeight.w400,
             ),
           ),

flutter_monisuo/lib/ui/pages/asset/components/holdings_section.dart

@@ -1,6 +1,6 @@
 import 'package:flutter/material.dart';
 import '../../../../core/theme/app_theme.dart';
-import '../../../../core/theme/app_color_scheme.dart';
+import '../../../../core/theme/app_theme_extension.dart';
 import '../../../../core/theme/app_spacing.dart';
 import '../../../../data/models/account_models.dart';
 import '../../../components/glass_panel.dart';
@@ -116,11 +116,9 @@ class HoldingRow extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    final colorScheme = Theme.of(context).colorScheme;
-    final isDark = Theme.of(context).brightness == Brightness.dark;
-    final accentColor = isDark ? colorScheme.secondary : colorScheme.primary;
+    final accentColor = context.appColors.accentPrimary;
     final accentBgColor = accentColor.withValues(alpha: 0.1);
-    final profitColor = isProfit ? AppColorScheme.getUpColor(isDark) : AppColorScheme.getDownColor(isDark);
+    final profitColor = isProfit ? context.appColors.up : context.appColors.down;
 
     return Padding(
       padding: const EdgeInsets.symmetric(horizontal: AppSpacing.md, vertical: 14),
@@ -159,7 +157,7 @@ class HoldingRow extends StatelessWidget {
                   quantity,
                   style: AppTextStyles.bodyMedium(context).copyWith(
                     fontWeight: FontWeight.w400,
-                    color: colorScheme.onSurfaceVariant,
+                    color: context.colors.onSurfaceVariant,
                   ),
                 ),
               ],

flutter_monisuo/lib/ui/pages/asset/components/records_link_row.dart

@@ -1,7 +1,7 @@
 import 'package:flutter/material.dart';
 import 'package:lucide_icons_flutter/lucide_icons.dart';
 import '../../../../core/theme/app_theme.dart';
-import '../../../../core/theme/app_color_scheme.dart';
+import '../../../../core/theme/app_theme_extension.dart';
 import '../../../../core/theme/app_spacing.dart';
 import '../../../components/glass_panel.dart';
 
@@ -16,9 +16,7 @@ class RecordsLinkRow extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    final colorScheme = Theme.of(context).colorScheme;
-    final isDark = Theme.of(context).brightness == Brightness.dark;
-    final mutedColor = isDark ? AppColorScheme.darkOnSurfaceMuted : colorScheme.onSurfaceVariant;
+    final mutedColor = context.appColors.onSurfaceMuted;
 
     return GestureDetector(
       onTap: onTap,