GET /api/voices/search?provider=cartesia&query=warm&language=en&gender=feminine

{
  "voices": [
    {
      "id": "f786b574-daa5-4673-aa0c-cbe3e8534c02",
      "name": "Warm Narrator",
      "description": "Conversational female voice",
      "gender": "feminine",
      "language": "en",
      "preview_url": null,
      "has_preview": true
    }
  ],
  "has_more": false,
  "next_cursor": null
}