- Audio cues: beep on record start (880Hz), double beep on stop (660Hz)
- Silence detection: auto-stop recording after 3s of silence (RMS-based)
- Continuous mode: auto-restart recording after agent responds
- Ctrl+R starts continuous mode, Ctrl+R during recording exits it
- Waits for TTS to finish before restarting to avoid recording speaker
- Tests: 7 new tests for beep generation and silence detection
The test was failing because GROQ_API_KEY leaked from the environment.
Now both VOICE_TOOLS_OPENAI_KEY and GROQ_API_KEY are removed to
properly test the "no STT key" scenario.