AppWindow is wrongly resized when changing Fullscreen to Normal mode

[Commode3]

Describe the bug

On an AppWindow, when setting its WindowState to Fullscreen, then resetting it to Normal, the window doesn't revert the size and position; instead it resizes to the entire screen.

Lightest Sample Project to demonstrate the issue

AppWindowFullscreenBug.zip

Desktop/Platform specs

• OS: Windows 11 24H2
• AvaloniaUI: 11.2.3 (latest)
• FluentAvalonia: 2.2.0 (latest)

Additional context

This issue can be observed in the attached sample project (same as above).

After debugging the code (of the master branch), this bug occurs because the AppWindow size is saved using the Win32 API after Avalonia has already changed the size by itself. Therefore, the restored size is wrong.

I'm about to create a PR that fixes this bug. Actually, according to my limited tests, only a conditional move of the OnPropertyChanged propagation (when the fullscreen is enabled) is needed.
However, I might be mistaken, as I may not have reviewed all the AppWindow breaking changes that could prevent this fix.