Function headless 

pub fn headless(path: &str) -> PaneHeadless

Create a PaneHeadless instance — no GPU required.

Loads the layout from path and initialises all widget state. Styles and textures are stubbed out; only widget logic runs.

Set headless_accessible: true in your root definition to enable PaneHeadless::press.

Panics

Panics if the .ron file cannot be read or parsed.