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/home/profit_analysis_page.dart

@@ -2,8 +2,8 @@ import 'package:flutter/material.dart';
 import 'package:provider/provider.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_spacing.dart';
+import '../../../core/theme/app_theme_extension.dart';
 import '../../../data/services/asset_service.dart';
 
 /// 盈亏分析页面 - 月度盈亏日历
@@ -26,26 +26,6 @@ class _ProfitAnalysisPageState extends State<ProfitAnalysisPage> {
     WidgetsBinding.instance.addPostFrameCallback((_) => _loadProfit());
   }
 
-  // ============================================
-  // 主题感知颜色
-  // ============================================
-
-  bool get _isDark => Theme.of(context).brightness == Brightness.dark;
-
-  Color get _upColor => AppColorScheme.getUpColor(_isDark);
-  Color get _downColor => AppColorScheme.getDownColor(_isDark);
-
-  Color get _scaffoldBg =>
-      _isDark ? AppColorScheme.darkBackground : AppColorScheme.lightBackground;
-
-  Color get _cardBg => _isDark
-      ? AppColorScheme.darkSurfaceContainer
-      : AppColorScheme.lightSurfaceLowest;
-
-  Color get _cardBorder => _isDark
-      ? AppColorScheme.darkOutlineVariant.withValues(alpha: 0.15)
-      : AppColorScheme.lightOutlineVariant.withValues(alpha: 0.5);
-
   // ============================================
   // 数据加载
   // ============================================
@@ -111,16 +91,15 @@ class _ProfitAnalysisPageState extends State<ProfitAnalysisPage> {
 
   @override
   Widget build(BuildContext context) {
-    final colorScheme = Theme.of(context).colorScheme;
     final now = DateTime.now();
     final isCurrentMonth =
         _currentMonth.year == now.year && _currentMonth.month == now.month;
 
     return Scaffold(
-      backgroundColor: _scaffoldBg,
+      backgroundColor: context.colors.surface,
       appBar: AppBar(
         title: const Text('盈亏分析'),
-        backgroundColor: _scaffoldBg,
+        backgroundColor: context.colors.surface,
         elevation: 0,
         scrolledUnderElevation: 0,
         centerTitle: true,
@@ -130,31 +109,30 @@ class _ProfitAnalysisPageState extends State<ProfitAnalysisPage> {
         child: Container(
           padding: EdgeInsets.all(AppSpacing.lg),
           decoration: BoxDecoration(
-            color: _cardBg,
+            color: context.appColors.surfaceCard,
             borderRadius: BorderRadius.circular(AppRadius.xl),
-            border: Border.all(color: _cardBorder),
+            border: Border.all(color: context.appColors.ghostBorder),
           ),
           child: Column(
             mainAxisSize: MainAxisSize.min,
             children: [
               // 月度盈亏摘要
-              _buildSummarySection(colorScheme),
+              _buildSummarySection(),
               SizedBox(height: AppSpacing.md),
 
               // 月份导航
-              _buildMonthNavigation(colorScheme, isCurrentMonth),
+              _buildMonthNavigation(isCurrentMonth),
               SizedBox(height: AppSpacing.sm),
 
               // 星期标题
-              _buildWeekdayHeaders(colorScheme),
+              _buildWeekdayHeaders(),
               SizedBox(height: AppSpacing.xs),
 
               // 日历网格
               if (_isLoading)
-                _buildLoadingIndicator(colorScheme)
+                _buildLoadingIndicator()
               else
                 ..._buildCalendarGrid(
-                  colorScheme,
                   now,
                   isCurrentMonth,
                 ),
@@ -166,16 +144,18 @@ class _ProfitAnalysisPageState extends State<ProfitAnalysisPage> {
   }
 
   /// 月度盈亏摘要
-  Widget _buildSummarySection(ColorScheme colorScheme) {
+  Widget _buildSummarySection() {
+    final upColor = context.appColors.up;
+    final downColor = context.appColors.down;
     final isProfit = _monthProfit >= 0;
-    final color = _isLoading ? colorScheme.onSurfaceVariant : (isProfit ? _upColor : _downColor);
+    final color = _isLoading ? context.colors.onSurfaceVariant : (isProfit ? upColor : downColor);
 
     return Column(
       children: [
         Text(
           '月度盈亏',
           style: AppTextStyles.bodyMedium(context).copyWith(
-            color: colorScheme.onSurfaceVariant,
+            color: context.colors.onSurfaceVariant,
           ),
         ),
         SizedBox(height: AppSpacing.xs),
@@ -193,7 +173,7 @@ class _ProfitAnalysisPageState extends State<ProfitAnalysisPage> {
   }
 
   /// 月份导航行
-  Widget _buildMonthNavigation(ColorScheme colorScheme, bool isCurrentMonth) {
+  Widget _buildMonthNavigation(bool isCurrentMonth) {
     return Row(
       mainAxisAlignment: MainAxisAlignment.spaceBetween,
       children: [
@@ -203,13 +183,13 @@ class _ProfitAnalysisPageState extends State<ProfitAnalysisPage> {
           child: Container(
             padding: EdgeInsets.all(AppSpacing.xs + 1),
             decoration: BoxDecoration(
-              color: colorScheme.surfaceContainerHigh,
+              color: context.colors.surfaceContainerHigh,
               borderRadius: BorderRadius.circular(AppRadius.sm),
             ),
             child: Icon(
               LucideIcons.chevronLeft,
               size: 16,
-              color: colorScheme.onSurfaceVariant,
+              color: context.colors.onSurfaceVariant,
             ),
           ),
         ),
@@ -227,16 +207,16 @@ class _ProfitAnalysisPageState extends State<ProfitAnalysisPage> {
             padding: EdgeInsets.all(AppSpacing.xs + 1),
             decoration: BoxDecoration(
               color: isCurrentMonth
-                  ? colorScheme.surfaceContainerHigh.withValues(alpha: 0.5)
-                  : colorScheme.surfaceContainerHigh,
+                  ? context.colors.surfaceContainerHigh.withValues(alpha: 0.5)
+                  : context.colors.surfaceContainerHigh,
               borderRadius: BorderRadius.circular(AppRadius.sm),
             ),
             child: Icon(
               LucideIcons.chevronRight,
               size: 16,
               color: isCurrentMonth
-                  ? colorScheme.onSurfaceVariant.withValues(alpha: 0.4)
-                  : colorScheme.onSurfaceVariant,
+                  ? context.colors.onSurfaceVariant.withValues(alpha: 0.4)
+                  : context.colors.onSurfaceVariant,
             ),
           ),
         ),
@@ -245,7 +225,7 @@ class _ProfitAnalysisPageState extends State<ProfitAnalysisPage> {
   }
 
   /// 星期标题行
-  Widget _buildWeekdayHeaders(ColorScheme colorScheme) {
+  Widget _buildWeekdayHeaders() {
     return Row(
       children: ['一', '二', '三', '四', '五', '六', '日'].map((d) {
         return Expanded(
@@ -254,7 +234,7 @@ class _ProfitAnalysisPageState extends State<ProfitAnalysisPage> {
               d,
               style: AppTextStyles.bodySmall(context).copyWith(
                 fontWeight: FontWeight.w500,
-                color: colorScheme.onSurfaceVariant.withValues(alpha: 0.6),
+                color: context.colors.onSurfaceVariant.withValues(alpha: 0.6),
               ),
             ),
           ),
@@ -264,7 +244,7 @@ class _ProfitAnalysisPageState extends State<ProfitAnalysisPage> {
   }
 
   /// 加载指示器
-  Widget _buildLoadingIndicator(ColorScheme colorScheme) {
+  Widget _buildLoadingIndicator() {
     return Padding(
       padding: EdgeInsets.symmetric(vertical: AppSpacing.xxl),
       child: Center(
@@ -273,7 +253,7 @@ class _ProfitAnalysisPageState extends State<ProfitAnalysisPage> {
           height: 20,
           child: CircularProgressIndicator(
             strokeWidth: 2,
-            color: colorScheme.primary,
+            color: context.colors.primary,
           ),
         ),
       ),
@@ -282,10 +262,11 @@ class _ProfitAnalysisPageState extends State<ProfitAnalysisPage> {
 
   /// 日历网格
   List<Widget> _buildCalendarGrid(
-    ColorScheme colorScheme,
     DateTime now,
     bool isCurrentMonth,
   ) {
+    final upColor = context.appColors.up;
+    final downColor = context.appColors.down;
     final firstDayOfMonth = DateTime(_currentMonth.year, _currentMonth.month, 1);
     final daysInMonth =
         DateTime(_currentMonth.year, _currentMonth.month + 1, 0).day;
@@ -313,16 +294,16 @@ class _ProfitAnalysisPageState extends State<ProfitAnalysisPage> {
               margin: EdgeInsets.all(1),
               decoration: BoxDecoration(
                 color: isToday
-                    ? colorScheme.primary.withValues(alpha: 0.12)
+                    ? context.colors.primary.withValues(alpha: 0.12)
                     : hasProfit
                         ? (profit! > 0
-                            ? _upColor.withValues(alpha: 0.08)
-                            : _downColor.withValues(alpha: 0.08))
+                            ? upColor.withValues(alpha: 0.08)
+                            : downColor.withValues(alpha: 0.08))
                         : Colors.transparent,
                 borderRadius: BorderRadius.circular(AppRadius.sm),
                 border: isToday
                     ? Border.all(
-                        color: colorScheme.primary.withValues(alpha: 0.4),
+                        color: context.colors.primary.withValues(alpha: 0.4),
                         width: 1,
                       )
                     : null,
@@ -336,8 +317,8 @@ class _ProfitAnalysisPageState extends State<ProfitAnalysisPage> {
                       fontSize: 10,
                       fontWeight: isToday ? FontWeight.bold : FontWeight.w400,
                       color: isToday
-                          ? colorScheme.primary
-                          : colorScheme.onSurface,
+                          ? context.colors.primary
+                          : context.colors.onSurface,
                     ),
                   ),
                   if (hasProfit) ...[
@@ -347,7 +328,7 @@ class _ProfitAnalysisPageState extends State<ProfitAnalysisPage> {
                       style: TextStyle(
                         fontSize: 7,
                         fontWeight: FontWeight.w600,
-                        color: profit > 0 ? _upColor : _downColor,
+                        color: profit > 0 ? upColor : downColor,
                       ),
                       maxLines: 1,
                       overflow: TextOverflow.ellipsis,