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.
Implements Issue #314 Phase 2 & 3: - /voice command to toggle voice mode (on/off/tts/status) - Ctrl+Space push-to-talk recording via sounddevice - Whisper STT transcription via existing transcription_tools - Optional TTS response playback via existing tts_tool - Visual indicators in prompt (recording/transcribing/voice) - 21 unit tests, all mocked (no real mic/API) - Optional deps: sounddevice, numpy (pip install hermes-agent[voice])