Generates or edits images.

- You MUST provide a single detailed `subject` prompt for image generation or editing. - When using multiple `input`, you SHOULD describe each image's role directly in `subject`, e.g. `Image 1` for composition reference, `Image 2` for lighting reference, `Image 3` for background. - For text: you SHOULD add "sharp, legible, correctly spelled" for important text; keep text short