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/data/models/user.dart

@@ -0,0 +1,80 @@
+/// 用户模型
+class User {
+  final int id;
+  final String username;
+  final String? nickname;
+  final String? avatar;
+  final String? phone;
+  final String? email;
+  final int kycStatus;
+  final int status;
+  final DateTime? lastLoginTime;
+  final DateTime? createTime;
+
+  User({
+    required this.id,
+    required this.username,
+    this.nickname,
+    this.avatar,
+    this.phone,
+    this.email,
+    required this.kycStatus,
+    required this.status,
+    this.lastLoginTime,
+    this.createTime,
+  });
+
+  factory User.fromJson(Map<String, dynamic> json) {
+    return User(
+      id: json['id'] as int? ?? 0,
+      username: json['username'] as String? ?? '',
+      nickname: json['nickname'] as String?,
+      avatar: json['avatar'] as String?,
+      phone: json['phone'] as String?,
+      email: json['email'] as String?,
+      kycStatus: json['kycStatus'] as int? ?? 0,
+      status: json['status'] as int? ?? 1,
+      lastLoginTime: json['lastLoginTime'] != null
+          ? DateTime.tryParse(json['lastLoginTime'])
+          : null,
+      createTime: json['createTime'] != null
+          ? DateTime.tryParse(json['createTime'])
+          : null,
+    );
+  }
+
+  Map<String, dynamic> toJson() {
+    return {
+      'id': id,
+      'username': username,
+      'nickname': nickname,
+      'avatar': avatar,
+      'phone': phone,
+      'email': email,
+      'kycStatus': kycStatus,
+      'status': status,
+      'lastLoginTime': lastLoginTime?.toIso8601String(),
+      'createTime': createTime?.toIso8601String(),
+    };
+  }
+
+  /// 获取头像显示文字（用户名首字母）
+  String get avatarText =>
+      username.isNotEmpty ? username.substring(0, 1).toUpperCase() : 'U';
+
+  /// KYC 状态文字
+  String get kycStatusText {
+    switch (kycStatus) {
+      case 0:
+        return '未认证';
+      case 1:
+        return '审核中';
+      case 2:
+        return '已认证';
+      case 3:
+        return '认证失败';
+      default:
+        return '未知';
+    }
+  }
+}