Create text-to-video job

1. Submit job → get task_id
2. Poll status → wait until completed for a public URL

{
  "model": "viduq3-turbo",
  "prompt": "Camera on a woman sitting in a café; she looks toward the window as the camera drifts slowly, warm color grade, relaxed cozy mood.",
  "duration": 7,
  "seed": 3,
  "metadata": {
    "aspect_ratio": "16:9",
    "resolution": "1080p",
    "audio": true,
    "bgm": false,
    "off_peak": false,
    "callback_url": "https://your-api.com/v1/callback/vidu"
  }
}