feat(tsk_iRa5iBC4v7Tu): Flutter 客户端工程搭建(演示态)

基于 design/flutter/ 起步包在 client/ 下建立 Flutter 工程：

- pubspec.yaml：flutter_svg / lucide_icons / google_fonts 依赖；
  SVG 资产注册；字体由 google_fonts 运行时加载，无需本地 ttf
- lib/pangolin_theme.dart：完整设计令牌（色阶 / 间距 / 圆角 /
  动效 / 文字阶），PangolinText 改用 GoogleFonts getter，
  PangolinTheme.light / .dark 开箱即用
- lib/main.dart：runApp + 明暗主题 + 登录 → 引导 → 主框架 RootFlow
- lib/widgets/：全套组件雏形
    pangolin_icons    Lucide 图标映射
    pangolin_button   胶囊按钮四态
    country_code      国家码块 + 信号条
    status_pill       色点胶囊
    connect_button    核心连接键三态（off/connecting/on + 动画）
    server_tile       服务器列表行
    plan_card         套餐卡（专业版渐变高亮）
    auth_screen       登录 / 注册（邮箱验证码 + 设密码）
    onboarding_screen 首次引导 PageView（3 屏可滑动 + 进度点）
    home_shell        底部 4 Tab（连接/节点/统计/账户 + 状态机）
    account_screens   套餐选择 / 设备管理 / 兑换 / 联系我们
    pangolin_logo     PangolinMark / BrandLockup / AppIcon（SVG）
- assets/：logo-mark / logo-mark-white / logo-wordmark / app-icon（SVG）
- android/：Kotlin 主 Activity + Manifest + Gradle 配置
- ios/：Runner.xcodeproj + xcscheme + Podfile + AppDelegate + storyboard

运行方式（cd client/）：
  flutter pub get && flutter run

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

client/.metadata

@@ -0,0 +1,33 @@
+# This file tracks properties of this Flutter project.
+# Used by Flutter tool to assess capabilities and perform upgrades etc.
+#
+# This file should be version controlled.
+
+version:
+  revision: "a14f74ff3a1cbd521163c5f03d68113f6cfc50e6"
+  channel: "stable"
+
+project_type: app
+
+# Tracks metadata for the flutter migrate command
+migration:
+  platforms:
+    - platform: root
+      create_revision: a14f74ff3a1cbd521163c5f03d68113f6cfc50e6
+      base_revision: a14f74ff3a1cbd521163c5f03d68113f6cfc50e6
+    - platform: android
+      create_revision: a14f74ff3a1cbd521163c5f03d68113f6cfc50e6
+      base_revision: a14f74ff3a1cbd521163c5f03d68113f6cfc50e6
+    - platform: ios
+      create_revision: a14f74ff3a1cbd521163c5f03d68113f6cfc50e6
+      base_revision: a14f74ff3a1cbd521163c5f03d68113f6cfc50e6
+
+  # User provided section
+
+  # List of Local paths (relative to this file) that should be
+  # ignored by the migrate tool.
+  #
+  # Files that are not part of the templates will be ignored by default.
+  unmanaged_files:
+    - 'lib/main.dart'
+    - 'ios/Runner.xcodeproj/project.pbxproj'