dictation_toggle= as a named gesture rather than a bare flag.
The disk spelling and the API spelling are deliberately different. On disk it is 0/1, because that is the byte already written in every preferences.conf and three parsers read it. Over the API it is push_to_talk/toggle, because "dictation_gesture": "1" is a riddle at the call site - and the two parsers that read dictation_toggle disagree about true (one accepts it, one does not), which is exactly the kind of question a typed value should stop anybody having to ask.