Generate a motion graphics video using Remotion (React-based animations).

Creates animated explainer-style videos with text, icons, and visual elements based on a prompt. The animation code is generated by an LLM and rendered via Remotion.

Args: project_id: Project ID to add the video to prompt: Description of the motion graphic to generate duration: Duration in seconds. Default: auto aspect_ratio: Aspect ratio. Default: project's aspect ratio order_index: Position in timeline. Default: append at end voiceover: Voiceover script to sync animations with is_overlay: If "true", convert the video to an OverlayClip after generation attachments: Optional list of image/video files to include in the motion graphic

Returns: Success response with video data