No scaling on KDE

[squili]

What happened?

When using Kaiteki on KDE, no automatic app scaling occurs and there is no manual scaling override option

Expected behavior

Kaiteki should, at some point, automatically detect the desktop scaling and adapt to it. If this is too involved to implement soon, #437 would provide a good workaround.

How to reproduce

1. Set desktop scaling to non-standard value
2. Open Kaiteki
3. Observe the scaling

What platform are you seeing the issue on?

Linux / KDE Plasma

Additional context

aspect ratio note: i am on a framework 13" laptop, which has uncommon display dimensions

[Craftplacer]

Such issue is out-of-scope for me specifically, it seems like there already exists an issue for this on Flutter's repo: flutter/flutter#65517