Get streaming transcription WebSocket URL

curl --request GET \
  --url https://api.case.dev/voice/streaming/url \
  --header 'Authorization: Bearer <token>'

{
  "url": "wss://casemark-ai--websocket-stream-helper-fastapi-app.modal.run/ws",
  "connect_url": "wss://casemark-ai--websocket-stream-helper-fastapi-app.modal.run/ws?token=cm_1234567890abcdef",
  "protocol": "websocket",
  "audio_format": {
    "sample_rate": 16000,
    "encoding": "pcm_s16le",
    "channels": 1
  },
  "pricing": {
    "per_minute": 0.3,
    "per_hour": 18,
    "currency": "USD"
  }
}