OptionaltitleTitle displayed at the top of the GUI panel
OptionalwidthWidth of the GUI panel in pixels
OptionalcloseWhether folders should start closed
OptionalcontainerParent container element (defaults to document.body)
OptionalonCallback when close button is clicked (if provided, shows close button)
OptionalcloseTooltip text for the close button (e.g., "Close (R)")
Base configuration for GUI initialization