whitw window edges in dark mode

### Description of the new feature / enhancement

Hello,

When I open Power Toys, I also find it very helpful that the edges of the windows are highlighted in white in Dark Mode. This simple change makes them stand out very well from the windows behind them,

That’s why I would really appreciate it if all windows were set up this way.
Would it be possible for you to create a tool that does exactly that?
Perhaps with the option to configure the line style and thickness.

I would really appreciate it.
You make such great tools!!!

Best regards,
Manfred

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### Scenario when this would be used?

Perhaps with the option to configure the line style and thickness.

### Supporting information

_No response_

No file, test, or entry point is identified. Start by reviewing how PowerToys utilities interact with Windows desktop windows and whether an existing utility handles dark-mode window edges; a complete result would need a defined scope for all windows plus configurable line style and thickness.

Written by the indexing model from the issue text.