MilkDrop keyboard shortcuts not usable in fullscreen and desktop mode

When MilkDrop is in fullscreen or desktop mode it seems that there's no way to control it with the keyboard shortcuts (L, H, Space, etc.).

Would be nice to be able to select/browse the visualizations even in fullscreen mode. At least to be able to go to next visualization with Space or H.

For example if I want to open the MilkDrop visualization selector by pressing L it works in the windowed mode but in fullscreen pressing L just opens the file open dialog (as if the main Winamp window was active).

I'm not sure how it worked natively and I'm not sure how many conflicting keyboard shortcuts there would be for main Winamp usage vs MilkDrop. Personally the main keyboard actions I'd like to be able to use when in fullscreen MilkDrop mode would be changing the visualization (H, Space, L for MilkDrop) and maybe play/pause, next/previous track, toggle shuffle for track control (Winamp).

Info on how to control MilkDrop: https://www.youtube.com/watch?v=OQdZFlOHe5o (though this is for v3 but I think most shortcuts are the same for v2).

Ps. the function key shortcuts for MilkDrop don't seem to work even in windowed mode (e.g. F1, F4, F11) but I'm not sure if this is due to Webamp or because the OS or other app is stealing those shortcuts on this macOS I'm using. Might be worth checking if those could be made to work too if they don't.

Start by reproducing the missing keyboard shortcuts in MilkDrop fullscreen and desktop modes, then trace how focus and keyboard events are handled for the visualization selector. Done means the requested MilkDrop shortcuts, including changing visualizations with Space or H, work in those modes without triggering conflicting main-window actions; function-key behavior remains worth checking separately.

Written by the indexing model from the issue text.