Mouse events posted with CGEventPostToPid reach the target app with no
window association, so AppKit never routes the press to a view: hover
states fire but the control is never activated, and the mouseUp is
dropped outright when posted back-to-back. Post click events to the HID
event tap instead (as keyboard synthesis already does), pace them, and
stamp mouseEventClickState so multi-clicks register.
Synthetic clicks now also report verification unverified/synthetic_input
from the helper itself, matching the other synthetic actions.