Proposal : It is hoped that the equivalent API of UWP on the desktop can be provided in the Windows App SDK

Nobody has claimed this yet.

### Describe the bug

希望能在 Windows App SDK 中提供 UWP 在桌面被限制的等价 API
It is hoped that the equivalent API of UWP on the desktop can be provided in the Windows App SDK

As the title suggests, there are many apis in Windows UWP that are limited to one platform, such as ShutdownManager, ProcessLauncher, TimeZoneSettings, and so on. These apis are not available either in UWP mode or desktop application mode, and if you want to use this part of the content, you need to call the corresponding Win32 API or COM interface. In the future, I hope the Windows App SDK team can consider this part and provide a flat API, which is not restricted by any restrictions, and is convenient for desktop applications to call.
如标题所示，在 Windows UWP 中，有很多 API 都是限制于某种平台下才可以使用的，比如 ShutdownManager，ProcessLauncher，TimeZoneSettings等等。这些 API 不管是在 UWP 模式下，还是桌面应用模式下，都不可用，如果想要使用这一部分的内容，就需要调用相应的 Win32 API 或 COM 接口。未来希望 Windows App SDK 团队能考虑一下这一部分，提供一个平替的 API，这个 API 不受任何限制，方便桌面应用调用。

### Steps to reproduce the bug

See describe

### Expected behavior

未来希望 Windows App SDK 团队能考虑一下这一部分，提供一个平替的 API，这个 API 不受任何限制，方便桌面应用调用。
In the future, I hope the Windows App SDK team can consider this part and provide a flat API, which is not restricted by any restrictions, and is convenient for desktop applications to call.

### Screenshots


### NuGet package version

Windows App SDK 1.5.0: 1.5.240227000

### Packaging type

Packaged (MSIX)

### Windows version

Insider Build (xxxxx)

### IDE

Visual Studio 2022

### Additional context

None

The issue identifies no source files, tests, or entry points and proposes equivalent APIs for ShutdownManager, ProcessLauncher, and TimeZoneSettings. Start by reviewing the existing Windows App SDK surface and the corresponding Win32 or COM interfaces, then define a narrowly scoped API and clear acceptance criteria before implementation.

Written by the indexing model from the issue text.