Seedance 2.0 Fast API

# 1. Create the job. 202 Accepted; the body carries the task id,
#    the pre-charged price, and a poll_url. Reuse one Idempotency-Key
#    across retries so a timeout never starts a second paid job.
curl --fail-with-body https://api.omniakey.com/v1/media/tasks \
  -H "Authorization: Bearer $OMNIAKEY_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: dreamina-seedance-2-0-fast-260128-001" \
  -d '{
    "model": "dreamina-seedance-2-0-fast-260128",
    "type": "video",
    "operation": "text_to_video",
    "input": {"prompt": "a paper boat on a quiet lake at sunset"},
    "parameters": {"duration": 6, "resolution": "720p"}
  }'

# 2. The same model id and the same poll loop serve the other operations:
#      image_to_video         media[] type "first_frame"
#      reference_to_video     media[] type "reference_image"
#    Reference media travel alongside the prompt:
#    {"prompt": "...", "media": [{"type": "first_frame", "url": "https://example.com/first-frame.png"}]}
#    A public HTTPS URL or a base64 data URI both work.

# 3. Poll GET /v1/media/tasks/{id} until status is
#    succeeded | failed | canceled. Progress carries percent and stage.
curl --fail-with-body https://api.omniakey.com/v1/media/tasks/TASK_ID \
  -H "Authorization: Bearer $OMNIAKEY_API_KEY"

# 4. Download assets[0].url before expires_at, or poll again for a
#    fresh signed URL. Failed and canceled jobs are refunded.
curl -sS -o out.mp4 "$(jq -r '.assets[0].url' result.json)"