Alias for action_later so the app-level Esc handler defers.
The app's action_interrupt (escape binding, priority=True)
fires before this screen's own escape binding. When the active
screen is a ModalScreen, it dispatches to action_cancel if
present, else falls through to dismiss(None). Without this
alias, Esc would dismiss with None, which the caller treats as
a programmatic dismiss (no toast, no reopen) instead of an
explicit defer.
