I used Godot’s GUI skinning ability to create an in-battle interface. It looks like this:

Don’t mind the placeholder text. I think most of the content is self explanatory. The list at the top can be used to spawn programs at the start of the battle, with the number to the right of each being the quantity available. The arrows to the right of the exit button can be used to move the interface to the left or right of the screen.
The font is Share Tech Mono. The Slingshot and Swiss Army Knife icons on the grid are by Freepik from www.flaticon.com.