curl https://api-dev.qcall.ai/tts/webhooks \
  -H "Authorization: Bearer your-api-key"

{
  "webhooks": [
    {
      "id": "wh-123",
      "url": "https://example.com/webhook",
      "events": ["tts.completed", "stt.completed"],
      "status": "active",
      "created_at": "2026-01-15T10:00:00Z"
    }
  ]
}