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/hooks/useSettingsForm.ts

@@ -81,6 +81,7 @@ export function useSettingsForm(): UseSettingsFormResult {
       ...data,
       showInTray: data.showInTray ?? true,
       minimizeToTrayOnClose: data.minimizeToTrayOnClose ?? true,
+      useAppWindowControls: data.useAppWindowControls ?? false,
       enableClaudePluginIntegration:
         data.enableClaudePluginIntegration ?? false,
       silentStartup: data.silentStartup ?? false,
@@ -105,6 +106,7 @@ export function useSettingsForm(): UseSettingsFormResult {
           ({
             showInTray: true,
             minimizeToTrayOnClose: true,
+            useAppWindowControls: false,
             enableClaudePluginIntegration: false,
             skipClaudeOnboarding: false,
             language: readPersistedLanguage(),
@@ -139,6 +141,7 @@ export function useSettingsForm(): UseSettingsFormResult {
         ...serverData,
         showInTray: serverData.showInTray ?? true,
         minimizeToTrayOnClose: serverData.minimizeToTrayOnClose ?? true,
+        useAppWindowControls: serverData.useAppWindowControls ?? false,
         enableClaudePluginIntegration:
           serverData.enableClaudePluginIntegration ?? false,
         silentStartup: serverData.silentStartup ?? false,