With multiple full windows, each renderer independently reacts to the
same backend event, so one-shot cues fired N times: OS notifications
(the per-renderer throttle can't see other windows), the turn-end sound
(playCompletionSound runs on every message.complete, ungated by focus),
and auto-spoken replies (double voice when a chat is open in two windows).
Add a single race-free owner in the main process (electron/event-dedupe.ts):
main handles IPC serially, so the first window to claim a key within a
short window wins and peers stay quiet. Notifications collapse at the
hermes:notify choke point; the sound and spoken replies claim via a new
hermes:ambient:claim IPC (keyed by session / reply id). Off Electron the
claim falls back to "emit", preserving single-window behavior.
The sound's mute check runs before the claim so a muted window can't win
the cue and silence an audible peer.
Brooklyn Nicholson