Implement Real-time Voice Alerts with Cartesia

Design and implement a real-time voice alert mechanism for critical fraud detections using Cartesia. When the agent identifies a high-severity fraud, it should synthesize a clear, concise voice message detailing the alert and play it (or save to an audio file). Provide a Python function `send_voice_alert(message: str)` that uses Cartesia's API. Show how the Claude agent would invoke this tool as part of its `trigger_alert` process.