Module app 

Constants

SCREENSHOT

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 a JSON envelope {format, size_bytes, data_base64}.

WINDOWS

Enumerate the host app’s top-level windows. Returns a JSON array of {id, title, focused, main, visible, width, height}.