feat(client): 三端布局架构 + macOS 桌面端 + app 图标

三端布局(mobile/tablet/desktop):
- core/responsive/form_factor.dart 形态判定 + shell/ 分发器(home_shell→desktop/mobile)
- desktop_shell 对照 ui_kits/desktop/dapp.jsx: 侧栏204·6项 + 套餐卡 + 顶栏(标题/状态/主题切换) + 连接页居中单列
- 新增组件 nav_sidebar / plan_badge_card / content_top_bar / bottom_tab_bar
- 新增一级页 contact_page / settings_page; navigation_provider(NavView)
- 删除旧 widgets/home_shell.dart(逻辑迁入 shell/)

macOS 桌面端:
- 窗口默认 920×600 + 最小 720×560(MainFlutterWindow.swift)
- app 图标替换为穿山甲(AppIcon.appiconset 全套, 由 app-icon.svg 渲染)

其余(本会话):
- Phase2 接线: auth_api/token_store/auth_provider/vpn_bridge_provider + 真实 connection/nodes
- lucide_icons 兼容补丁(packages/lucide_icons_patched) 修复 IconData final 报错
- 测试修复: connect_passthrough(UTF-8) / harness / golden @Skip
- l10n 新增 settingsTitle

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

client/.metadata

@@ -1,10 +1,10 @@
 # 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.
+# This file should be version controlled and should not be manually edited.
 
 version:
-  revision: "a14f74ff3a1cbd521163c5f03d68113f6cfc50e6"
+  revision: "559ffa3f75e7402d65a8def9c28389a9b2e6fe42"
   channel: "stable"
 
 project_type: app
@@ -13,14 +13,11 @@ project_type: app
 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
+      create_revision: 559ffa3f75e7402d65a8def9c28389a9b2e6fe42
+      base_revision: 559ffa3f75e7402d65a8def9c28389a9b2e6fe42
+    - platform: macos
+      create_revision: 559ffa3f75e7402d65a8def9c28389a9b2e6fe42
+      base_revision: 559ffa3f75e7402d65a8def9c28389a9b2e6fe42
 
   # User provided section