Attaches a single keydown listener to options.listenerTarget
(default document). Matching chord subscriptions invoke options.onForward
with a DOM-shape payload AND push a keys.action envelope back to the
owning napplet via the per-window send callback captured at
keys.registerAction time. Returns a ServiceHandler augmented with a
destroy() method that detaches the listener and clears all registries.
Create a keys service handler.
Attaches a single
keydownlistener tooptions.listenerTarget(defaultdocument). Matching chord subscriptions invokeoptions.onForwardwith a DOM-shape payload AND push akeys.actionenvelope back to the owning napplet via the per-windowsendcallback captured atkeys.registerActiontime. Returns aServiceHandleraugmented with adestroy()method that detaches the listener and clears all registries.