curl --request POST \
  --url https://omnimux.ai/api/social/v1/media/presign \
  --header 'Authorization: Bearer <access_token>' \
  --header 'New-Api-User: <user_id>' \
  --header 'Content-Type: application/json' \
  --data '{"filename":"a.png","contentType":"image/png"}'

{"success":true,"data":{"upload_url":"https://...","public_url":"https://..."}}

{
  "success": false,
  "message": "Unauthorized"
}

{
  "success": false,
  "message": "Insufficient quota. Please top up your account."
}

{
  "success": false,
  "message": "Forbidden"
}

{
  "success": false,
  "message": "Not found"
}

{
  "success": false,
  "message": "Rate limit exceeded"
}

{
  "success": false,
  "message": "Internal server error"
}