pub const SCREENSHOT: &'static str;Expand description
Capture a PNG of the host app’s window. Accepts an optional
window_id (returned by WINDOWS) so multi-window desktop
apps can pick a specific surface; mobile platforms ignore it
since they have a single foreground window. Returns the unified
screenshot envelope {target, kind, coordinate_space, format, width, height, size_bytes, image:{mime, encoding, data}}.