refactor: 将前端从 uni-app x 重构为 Flutter

变更内容:
- 删除 uni-app x 项目 (app/ 目录)
- 新增 Flutter 项目 (flutter_monisuo/ 目录)
- 新增部署脚本 (deploy/ 目录)

Flutter 项目功能:
- 用户登录/注册
- 首页资产概览
- 行情币种列表
- 交易买卖操作
- 资产账户管理
- 充值/提现/划转
- 深色主题
- JWT Token 认证

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

flutter_monisuo/lib/ui/pages/main/main_page.dart

@@ -0,0 +1,136 @@
+import 'package:flutter/material.dart';
+import '../../../core/constants/app_colors.dart';
+import '../home/home_page.dart';
+import '../market/market_page.dart';
+import '../trade/trade_page.dart';
+import '../asset/asset_page.dart';
+import '../mine/mine_page.dart';
+
+/// 主页面（包含底部导航）
+class MainPage extends StatefulWidget {
+  const MainPage({super.key});
+
+  @override
+  State<MainPage> createState() => _MainPageState();
+}
+
+class _MainPageState extends State<MainPage> {
+  int _currentIndex = 0;
+
+  final List<Widget> _pages = [
+    const HomePage(),
+    const MarketPage(),
+    const TradePage(),
+    const AssetPage(),
+    const MinePage(),
+  ];
+
+  final List<_TabItem> _tabs = [
+    _TabItem('首页', Icons.home_outlined, Icons.home),
+    _TabItem('行情', Icons.show_chart_outlined, Icons.show_chart),
+    _TabItem('交易', Icons.swap_horiz_outlined, Icons.swap_horiz),
+    _TabItem('资产', Icons.account_balance_wallet_outlined, Icons.account_balance_wallet),
+    _TabItem('我的', Icons.person_outline, Icons.person),
+  ];
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      body: IndexedStack(
+        index: _currentIndex,
+        children: _pages,
+      ),
+      bottomNavigationBar: _buildBottomNav(),
+    );
+  }
+
+  Widget _buildBottomNav() {
+    return Container(
+      decoration: const BoxDecoration(
+        color: AppColors.cardBackground,
+        border: Border(top: BorderSide(color: AppColors.border)),
+      ),
+      child: SafeArea(
+        child: Padding(
+          padding: const EdgeInsets.symmetric(vertical: 8),
+          child: Row(
+            mainAxisAlignment: MainAxisAlignment.spaceAround,
+            children: _tabs.asMap().entries.map((entry) {
+              final index = entry.key;
+              final tab = entry.value;
+              final isSelected = index == _currentIndex;
+
+              return GestureDetector(
+                onTap: () => setState(() => _currentIndex = index),
+                behavior: HitTestBehavior.opaque,
+                child: Container(
+                  padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 8),
+                  child: Column(
+                    mainAxisSize: MainAxisSize.min,
+                    children: [
+                      Icon(
+                        isSelected ? tab.selectedIcon : tab.icon,
+                        color: isSelected ? AppColors.primary : AppColors.textSecondary,
+                        size: 24,
+                      ),
+                      const SizedBox(height: 4),
+                      Text(
+                        tab.label,
+                        style: TextStyle(
+                          fontSize: 12,
+                          color: isSelected ? AppColors.primary : AppColors.textSecondary,
+                        ),
+                      ),
+                    ],
+                  ),
+                ),
+              );
+            }).toList(),
+          ),
+        ),
+      ),
+    );
+  }
+}
+
+class _TabItem {
+  final String label;
+  final IconData icon;
+  final IconData selectedIcon;
+
+  _TabItem(this.label, this.icon, this.selectedIcon);
+}
+
+/// IndexedStack 用于保持页面状态
+class IndexedStack extends StatefulWidget {
+  final int index;
+  final List<Widget> children;
+
+  const IndexedStack({
+    super.key,
+    required this.index,
+    required this.children,
+  });
+
+  @override
+  State<IndexedStack> createState() => _IndexedStackState();
+}
+
+class _IndexedStackState extends State<IndexedStack> {
+  @override
+  Widget build(BuildContext context) {
+    return Stack(
+      children: widget.children.asMap().entries.map((entry) {
+        return Positioned.fill(
+          child: Offstage(
+            offstage: entry.key != widget.index,
+            child: TickerMode(
+              enabled: entry.key == widget.index,
+              child: entry.value,
+            ),
+          ),
+        );
+      }).toList(),
+    );
+  }
+}