添加应用级别窗口按钮，以改善linux wayland下系统窗口按钮失效的问题 (#1119)

* feat(window): add app-level window controls with settings toggle

Add a persistent settings toggle to enable app-level minimize/maximize/close controls and hide system decorations when enabled, providing a Wayland-friendly fallback for broken native titlebar interactions.

Co-authored-by: Cursor <cursoragent@cursor.com>

* fix(window): restrict app-level window controls to Linux only and fix startup flicker

- Guard useAppWindowControls with isLinux() in App.tsx so it's always
  false on macOS/Windows even if persisted as true
- Wrap set_decorations call in lib.rs with #[cfg(target_os = "linux")]
- Only show the toggle in WindowSettings on Linux
- Skip setDecorations effect while settingsData is still loading to
  prevent the Rust-side decoration state from being overridden by the
  undefined->false fallback, which caused a brief title bar flicker

---------

Co-authored-by: wzk <wx13571681304@outlook.com>
Co-authored-by: Cursor <cursoragent@cursor.com>
Co-authored-by: Jason <farion1231@gmail.com>

src/types.ts

@@ -244,6 +244,8 @@ export interface Settings {
   showInTray: boolean;
   // 点击关闭按钮时是否最小化到托盘而不是关闭应用
   minimizeToTrayOnClose: boolean;
+  // 是否启用应用级窗口控制按钮（最小化/最大化/关闭）
+  useAppWindowControls?: boolean;
   // 启用 Claude 插件联动（写入 ~/.claude/config.json 的 primaryApiKey）
   enableClaudePluginIntegration?: boolean;
   // 跳过 Claude Code 初次安装确认（写入 ~/.claude.json 的 hasCompletedOnboarding）