Function spawn_voice_steer 

fn spawn_voice_steer(
    liaison_endpoint: &str,
    session_id: &str,
    user_id: &str,
    chat_cfg: &ChatConfig,
)

Fire-and-forget a mid-turn VOICE steer (Ctrl+V during a running turn): record + ASR another utterance via a fresh voice session and let its transcript submit — Pilot steers it into the active turn. TTS is disabled here (the per-segment playback rides the main turn’s stream); we just drain this session’s events on a spawned task.