Regenerate video AI asset image edit based on stored payload from database.

This endpoint allows you to regenerate an image edit by providing the AsyncTask ID from the original generation.

The endpoint will:

1. Retrieve the original payload from the database
2. Determine the provider (freepik or byteplus) based on stored data
3. Reconstruct the request DTO from the stored payload
4. Call the appropriate wrapper function to regenerate the image

Args: async_task_id: The AsyncTask.id (UUID string) from the original generation db: Database session user: Authenticated user

Returns: dict with task_id and status of the new generation task