Function create_headless_robot_test 

pub fn create_headless_robot_test<F>(
    width: u32,
    height: u32,
    content: F,
) -> RobotTestRule<TestRenderer>
where
    F: FnMut() + 'static,

Create a headless robot test rule for testing without a real renderer.

This is useful for fast unit tests that don’t need actual rendering.