How a native-input action delivers its event relative to app focus.
Foreground means the dispatcher brings the target app to the front and
then posts a session-wide input event at whatever is frontmost. Robust, but
it steals the user’s focus.
Background posts the event directly to the target process via
CGEventPostToPid without activating it, so the user’s active window keeps
focus. Not every macOS app honors
background-delivered events, so the dispatcher falls back to Foreground
when no target PID resolves or the background post is rejected.
Defaults to Foreground so existing plans and serialized payloads are
unchanged.