fix(client): 默认 UI 品牌文案统一英文 Pangolin(窗口标题/托盘/安装包名/macOS 菜单栏)

默认 UI 语言是英文,但窗口标题(windowManager.setTitle)、MaterialApp title、
托盘 tooltip 与右键菜单、Windows 安装包显示名、macOS CFBundleName 硬编码中文,
中英混排。统一改英文品牌名;iOS 桌面图标名(CFBundleDisplayName=穿山甲)按
市场定位保留。托盘菜单文案后续可接 l10n(现契约无 tray 键)。

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FEVUXAbFT6bF1Qw27RHWoD

client/lib/system_tray.dart

@@ -58,11 +58,11 @@ class TrayService with TrayListener, WindowListener {
     await trayManager.setIcon(
       Platform.isWindows ? 'assets/tray_icon.ico' : 'assets/tray_icon.png',
     );
-    await trayManager.setToolTip('穿山甲 Pangolin');
+    await trayManager.setToolTip('Pangolin');
     await trayManager.setContextMenu(Menu(items: [
-      MenuItem(key: 'show', label: '显示主界面'),
+      MenuItem(key: 'show', label: 'Show Window'),
       MenuItem.separator(),
-      MenuItem(key: 'quit', label: '退出'),
+      MenuItem(key: 'quit', label: 'Quit'),
     ]));
   }