Add an OpenGL / hardware acceleration toggle to the Windows desktop app

The Windows desktop app currently has no option to enable OpenGL or GPU hardware-accelerated rendering. As a result the interface runs on software rendering at a very low frame rate.

The concrete problem: the mouse cursor stutters and lags whenever it moves inside the app window, and scrolling and navigation feel choppy. It is consistent and distracting during everyday use.

Request: add a simple on/off setting to enable OpenGL / GPU hardware acceleration for the app. On systems with a capable GPU this would render the UI smoothly at full frame rate and remove the cursor stutter completely.

If other users are seeing the same lag, please add a note so this gets visibility.