Upstream's voice chat talks while controls.push_to_talk is held, a key. In
VR the free hand's grip is push to talk while it holds neither the weapon's
foregrip nor the Warthog's wheel (it is no button of the game's there).
The VR options' PLAY page gets Voice chat: push to talk (grip), open mic or
off (audio.voice_chat); the controller page names the grip's talking.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>