Screenshot an Electron notch overlay with the real wallpaper behind it

Page.captureScreenshot over CDP renders only the page, so a transparent overlay window (like a notch panel) comes out on white with no desktop behind it. For framed shots, hide every other app with System Events (activate Finder first, because the frontmost app can't be hidden), read the panel's rect from the DOM plus window.screenX/screenY, then run screencapture -x -R x,y,w,h on that rect padded with wallpaper. Measure from the panel body, not the outer element that includes flared top corners, so the side margins match the bottom margin. Wait until the rect stays the same for about 1.5s before capturing, since cards and streamed text keep resizing the panel after the turn reports done.