feat: 设置页面新增货币选择器和语言选择器

- 设置页面从StatelessWidget改为StatefulWidget
- 新增货币选择器bottom sheet，支持USD/CNY/EUR/GBP/JPY/HKD
- 新增语言选择器bottom sheet，支持简体中文/繁體中文/English/日本語
- 通知开关改为可交互状态
- 货币subtitle动态显示已选货币代码和符号

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/genex-mobile/lib/features/profile/presentation/pages/settings_page.dart

@@ -1,13 +1,30 @@
 import 'package:flutter/material.dart';
 import '../../../../app/theme/app_colors.dart';
 import '../../../../app/theme/app_typography.dart';
+import '../../../../app/theme/app_spacing.dart';
 
 /// 设置页面
 ///
-/// 账号安全、通知、支付管理、语言、关于
+/// 账号安全、通知、支付管理、语言、货币、关于
-class SettingsPage extends StatelessWidget {
+/// 货币选择影响交易页面中的计价货币符号
+class SettingsPage extends StatefulWidget {
   const SettingsPage({super.key});
 
+  @override
+  State<SettingsPage> createState() => _SettingsPageState();
+}
+
+class _SettingsPageState extends State<SettingsPage> {
+  // 当前选中的货币 (实际应用中从持久化/状态管理读取)
+  _CurrencyOption _selectedCurrency = _currencyOptions[0]; // 默认 USD
+  String _selectedLanguage = '简体中文';
+
+  // 通知开关
+  bool _notifyTrade = true;
+  bool _notifyExpiry = true;
+  bool _notifyMarket = false;
+  bool _notifyMarketing = false;
+
   @override
   Widget build(BuildContext context) {
     return Scaffold(
@@ -16,39 +33,59 @@ class SettingsPage extends StatelessWidget {
         children: [
           // Account & Security
           _buildSection('账号与安全', [
-            _buildTile('手机号', subtitle: '138****8888', icon: Icons.phone_rounded),
+            _buildTile('手机号',
-            _buildTile('邮箱', subtitle: 'u***@email.com', icon: Icons.email_rounded),
+                subtitle: '138****8888', icon: Icons.phone_rounded),
+            _buildTile('邮箱',
+                subtitle: 'u***@email.com', icon: Icons.email_rounded),
             _buildTile('修改密码', icon: Icons.lock_rounded),
-            _buildTile('身份认证', subtitle: 'L1 基础认证', icon: Icons.verified_user_rounded, onTap: () {
+            _buildTile('身份认证',
+                subtitle: 'L1 基础认证',
+                icon: Icons.verified_user_rounded, onTap: () {
               Navigator.pushNamed(context, '/kyc');
             }),
           ]),
 
           // Payment
           _buildSection('支付管理', [
-            _buildTile('支付方式', subtitle: 'Visa •••• 4242', icon: Icons.credit_card_rounded),
+            _buildTile('支付方式',
-            _buildTile('银行账户', subtitle: 'BoA •••• 6789', icon: Icons.account_balance_rounded),
+                subtitle: 'Visa •••• 4242',
+                icon: Icons.credit_card_rounded),
+            _buildTile('银行账户',
+                subtitle: 'BoA •••• 6789',
+                icon: Icons.account_balance_rounded),
             _buildTile('支付密码', icon: Icons.password_rounded),
           ]),
 
           // Notifications
           _buildSection('通知设置', [
-            _buildSwitchTile('交易通知', true),
+            _buildSwitchTile('交易通知', _notifyTrade,
-            _buildSwitchTile('到期提醒', true),
+                (v) => setState(() => _notifyTrade = v)),
-            _buildSwitchTile('行情变动', false),
+            _buildSwitchTile('到期提醒', _notifyExpiry,
-            _buildSwitchTile('营销推送', false),
+                (v) => setState(() => _notifyExpiry = v)),
+            _buildSwitchTile('行情变动', _notifyMarket,
+                (v) => setState(() => _notifyMarket = v)),
+            _buildSwitchTile('营销推送', _notifyMarketing,
+                (v) => setState(() => _notifyMarketing = v)),
           ]),
 
           // General
           _buildSection('通用', [
-            _buildTile('语言', subtitle: '简体中文', icon: Icons.language_rounded),
+            _buildTile('语言',
-            _buildTile('货币', subtitle: 'USD', icon: Icons.attach_money_rounded),
+                subtitle: _selectedLanguage,
+                icon: Icons.language_rounded,
+                onTap: () => _showLanguagePicker(context)),
+            _buildTile('货币',
+                subtitle:
+                    '${_selectedCurrency.code} (${_selectedCurrency.symbol})',
+                icon: Icons.attach_money_rounded,
+                onTap: () => _showCurrencyPicker(context)),
             _buildTile('清除缓存', icon: Icons.cleaning_services_rounded),
           ]),
 
           // About
           _buildSection('关于', [
-            _buildTile('版本', subtitle: 'v1.0.0', icon: Icons.info_outline_rounded),
+            _buildTile('版本',
+                subtitle: 'v1.0.0', icon: Icons.info_outline_rounded),
             _buildTile('用户协议', icon: Icons.description_rounded),
             _buildTile('隐私政策', icon: Icons.privacy_tip_rounded),
             _buildTile('帮助中心', icon: Icons.help_outline_rounded),
@@ -59,7 +96,8 @@ class SettingsPage extends StatelessWidget {
             padding: const EdgeInsets.all(20),
             child: OutlinedButton(
               onPressed: () {
-                Navigator.of(context).pushNamedAndRemoveUntil('/', (_) => false);
+                Navigator.of(context)
+                    .pushNamedAndRemoveUntil('/', (_) => false);
               },
               style: OutlinedButton.styleFrom(
                 foregroundColor: AppColors.error,
@@ -74,6 +112,152 @@ class SettingsPage extends StatelessWidget {
     );
   }
 
+  // ============================================================
+  // Currency Picker
+  // ============================================================
+  void _showCurrencyPicker(BuildContext context) {
+    showModalBottomSheet(
+      context: context,
+      backgroundColor: Colors.transparent,
+      builder: (_) => Container(
+        decoration: const BoxDecoration(
+          color: AppColors.surface,
+          borderRadius: BorderRadius.vertical(top: Radius.circular(16)),
+        ),
+        child: Column(
+          mainAxisSize: MainAxisSize.min,
+          children: [
+            // Handle
+            Container(
+              margin: const EdgeInsets.only(top: 12),
+              width: 36,
+              height: 4,
+              decoration: BoxDecoration(
+                color: AppColors.gray200,
+                borderRadius: AppSpacing.borderRadiusFull,
+              ),
+            ),
+            // Title
+            Padding(
+              padding: const EdgeInsets.all(16),
+              child: Text('选择计价货币', style: AppTypography.h3),
+            ),
+            const Divider(height: 1),
+            // Currency list
+            ..._currencyOptions.map((option) {
+              final isSelected = _selectedCurrency.code == option.code;
+              return ListTile(
+                leading: Text(option.flag, style: const TextStyle(fontSize: 24)),
+                title: Text(
+                  '${option.name} (${option.code})',
+                  style: AppTypography.bodyMedium.copyWith(
+                    fontWeight: isSelected ? FontWeight.w600 : FontWeight.w400,
+                    color: isSelected
+                        ? AppColors.primary
+                        : AppColors.textPrimary,
+                  ),
+                ),
+                subtitle: Text(
+                  '符号: ${option.symbol}',
+                  style: AppTypography.caption,
+                ),
+                trailing: isSelected
+                    ? const Icon(Icons.check_circle_rounded,
+                        color: AppColors.primary, size: 22)
+                    : null,
+                onTap: () {
+                  setState(() => _selectedCurrency = option);
+                  Navigator.pop(context);
+                },
+              );
+            }),
+            // Note
+            Padding(
+              padding: const EdgeInsets.fromLTRB(16, 8, 16, 24),
+              child: Text(
+                '此设置影响交易页面中所有价格的计价货币显示',
+                style: AppTypography.caption.copyWith(
+                  color: AppColors.textTertiary,
+                ),
+                textAlign: TextAlign.center,
+              ),
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+
+  // ============================================================
+  // Language Picker
+  // ============================================================
+  void _showLanguagePicker(BuildContext context) {
+    final languages = [
+      ('简体中文', 'zh-CN', '🇨🇳'),
+      ('繁體中文', 'zh-TW', '🇹🇼'),
+      ('English', 'en', '🇺🇸'),
+      ('日本語', 'ja', '🇯🇵'),
+    ];
+
+    showModalBottomSheet(
+      context: context,
+      backgroundColor: Colors.transparent,
+      builder: (_) => Container(
+        decoration: const BoxDecoration(
+          color: AppColors.surface,
+          borderRadius: BorderRadius.vertical(top: Radius.circular(16)),
+        ),
+        child: Column(
+          mainAxisSize: MainAxisSize.min,
+          children: [
+            Container(
+              margin: const EdgeInsets.only(top: 12),
+              width: 36,
+              height: 4,
+              decoration: BoxDecoration(
+                color: AppColors.gray200,
+                borderRadius: AppSpacing.borderRadiusFull,
+              ),
+            ),
+            Padding(
+              padding: const EdgeInsets.all(16),
+              child: Text('选择语言', style: AppTypography.h3),
+            ),
+            const Divider(height: 1),
+            ...languages.map((lang) {
+              final (name, _, flag) = lang;
+              final isSelected = _selectedLanguage == name;
+              return ListTile(
+                leading: Text(flag, style: const TextStyle(fontSize: 24)),
+                title: Text(
+                  name,
+                  style: AppTypography.bodyMedium.copyWith(
+                    fontWeight: isSelected ? FontWeight.w600 : FontWeight.w400,
+                    color: isSelected
+                        ? AppColors.primary
+                        : AppColors.textPrimary,
+                  ),
+                ),
+                trailing: isSelected
+                    ? const Icon(Icons.check_circle_rounded,
+                        color: AppColors.primary, size: 22)
+                    : null,
+                onTap: () {
+                  setState(() => _selectedLanguage = name);
+                  Navigator.pop(context);
+                },
+              );
+            }),
+            const SizedBox(height: 24),
+          ],
+        ),
+      ),
+    );
+  }
+
+  // ============================================================
+  // Shared Builders
+  // ============================================================
   Widget _buildSection(String title, List<Widget> children) {
     return Column(
       crossAxisAlignment: CrossAxisAlignment.start,
@@ -90,22 +274,55 @@ class SettingsPage extends StatelessWidget {
     );
   }
 
-  Widget _buildTile(String title, {String? subtitle, IconData? icon, VoidCallback? onTap}) {
+  Widget _buildTile(String title,
+      {String? subtitle, IconData? icon, VoidCallback? onTap}) {
     return ListTile(
-      leading: icon != null ? Icon(icon, size: 22, color: AppColors.textSecondary) : null,
+      leading: icon != null
+          ? Icon(icon, size: 22, color: AppColors.textSecondary)
+          : null,
       title: Text(title, style: AppTypography.bodyMedium),
-      subtitle: subtitle != null ? Text(subtitle, style: AppTypography.caption) : null,
+      subtitle: subtitle != null
-      trailing: const Icon(Icons.chevron_right_rounded, size: 20, color: AppColors.textTertiary),
+          ? Text(subtitle, style: AppTypography.caption)
+          : null,
+      trailing: const Icon(Icons.chevron_right_rounded,
+          size: 20, color: AppColors.textTertiary),
       onTap: onTap ?? () {},
     );
   }
 
-  Widget _buildSwitchTile(String title, bool value) {
+  Widget _buildSwitchTile(
+      String title, bool value, ValueChanged<bool> onChanged) {
     return SwitchListTile(
       title: Text(title, style: AppTypography.bodyMedium),
       value: value,
-      onChanged: (_) {},
+      onChanged: onChanged,
       activeColor: AppColors.primary,
     );
   }
 }
+
+// ============================================================
+// Currency Options
+// ============================================================
+class _CurrencyOption {
+  final String code;
+  final String symbol;
+  final String name;
+  final String flag;
+
+  const _CurrencyOption({
+    required this.code,
+    required this.symbol,
+    required this.name,
+    required this.flag,
+  });
+}
+
+const _currencyOptions = [
+  _CurrencyOption(code: 'USD', symbol: '\$', name: '美元', flag: '🇺🇸'),
+  _CurrencyOption(code: 'CNY', symbol: '¥', name: '人民币', flag: '🇨🇳'),
+  _CurrencyOption(code: 'EUR', symbol: '€', name: '欧元', flag: '🇪🇺'),
+  _CurrencyOption(code: 'GBP', symbol: '£', name: '英镑', flag: '🇬🇧'),
+  _CurrencyOption(code: 'JPY', symbol: '¥', name: '日元', flag: '🇯🇵'),
+  _CurrencyOption(code: 'HKD', symbol: 'HK\$', name: '港币', flag: '🇭🇰'),
+];