[Requests and ideas] Support standard Window menu actions in macOS Sequoia

## Summary

On macOS Sequoia, the GitHub Copilot desktop app does not expose the standard macOS Window menu actions that are available in most native desktop applications.

## Expected behavior

The **Window** menu should include standard macOS window management options such as:

* Move & Resize
* Full Screen Tile
* Fill
* Center
* Other Sequoia window management actions provided by the OS

For example, VS Code and many other desktop applications expose these options automatically through the Window menu.

## Actual behavior

In the GitHub Copilot desktop app, the Window menu only contains:

* Minimize
* Zoom
* Bring All to Front
* Move to Monitor

The newer macOS Sequoia window management actions are not available.

## Screenshots

* Screenshot 1: VS Code Window menu showing Move & Resize, Full Screen Tile, Fill, Center, etc.
* Screenshot 2: GitHub Copilot Window menu showing only Minimize, Zoom, Bring All to Front, and Move to Monitor.

## Why this matters

These menu items provide quick access to native macOS window management features and improve consistency with other desktop apps. Users expect standard Sequoia window controls to be available through the Window menu.

该 issue 未指明任何文件或测试。首先定位应用的 macOS Window 菜单设置，并将其当前操作与报告中列出的标准 Sequoia 选项进行比较。完成标准是 Window 菜单提供 Move & Resize、Full Screen Tile、Fill、Center 以及其他适用的原生 Sequoia 窗口操作。

由索引模型根据 Issue 内容生成。