Auto-hide taskbar not appearing when WinUI 3 window is maximized (regression in Windows App SDK 2.0.1)

### Describe the bug

When the Windows taskbar is set to **auto-hide** and a WinUI 3 application window is **maximized**, moving the mouse to the edge of the screen does not reveal the taskbar.

This was previously reported in #8431 and marked as fixed in WinAppSDK 1.6, but the issue still reproduces with **Windows App SDK 1.8.x and 2.0.1** even in a **minimal application without `ExtendsContentIntoTitleBar`**.

### Why is this important?

The auto-hide taskbar is a common Windows configuration. When a WinUI 3 window is maximized, users cannot access the taskbar to switch apps or open the Start menu without first restoring the window — behavior that works correctly in standard Win32 applications.

### Steps to reproduce the bug

1. Enable auto-hide taskbar in Windows Settings.
2. Create a new minimal WinUI 3 application (no title bar customization):

**minimal.csproj**
```xml

net8.0-windows10.0.19041.0
10.0.17763.0
WinExe
true
None
enable
enable
x64
win-x64

```

**App.xaml.cs**
```csharp
public partial class App : Application
{
public App() => InitializeComponent();

protected override void OnLaunched(LaunchActivatedEventArgs e)
{
new MainWindow().Activate();
}
}
```

**MainWindow.xaml**
```xml

```

3. Build and run the application.
4. Maximize the window using the title bar maximize button.
5. Move the mouse to the edge of the screen where the taskbar is hidden.

### Actual behavior

The taskbar does not appear when the mouse is moved to the screen edge while the WinUI 3 window is maximized.

### Expected behavior

The auto-hidden taskbar should appear when the mouse is moved to the screen edge.

### Screenshots

_No response_

### NuGet package version

2.0.12

### Windows version

Windows 11 (24H2): Build 26100

### Additional context

Unlike #8431, this issue **does not require `ExtendsContentIntoTitleBar = true`**. It reproduces with a completely default window with no title bar or windowing customizations, suggesting the root cause differs from or was not fully resolved by the previous fix.

Start with the minimal.csproj, App.xaml.cs, and MainWindow.xaml reproduction using Windows App SDK 2.0.1 on Windows 11 24H2, then maximize the default window and test the auto-hidden taskbar at the screen edge. Done means identifying and fixing the behavior so the taskbar appears without requiring title-bar customization or restoring the window.

Written by the indexing model from the issue text.