fix(desktop): make computer use act on the app the user sees

- Hit-test coordinate input with Accessibility: Notification Center and the Dock keep
  full-screen click-through windows, so the window-list check rejected every click
- Count an AX press that times out while a sheet or modal opens as dispatched
- Keep the snapshot when nothing reached the app, in the helper and the service
- Type into any focusable element (terminals, combo boxes), send keys to sheets
  and popovers, accept common key aliases
- Complete menu presses that only highlight their item, observe open menus and
  submenus first, and show menu shortcuts in labels
- Fit the model projection under Mothership's computer result budget

Author: waleedlatif1