Generate or EDIT an image. This is the tool for ALL image models (kind=image — flux-1-schnell, recraft-v3, aurora, dall-e-3, gemini-3.1-flash-image, nano-banana, etc.). Synchronous (1–3 s): returns { imageUrl, modelId } DIRECTLY — there is no job to poll and no get_job step (that's video only). IMAGE-TO-IMAGE: pass referenceImageUrl (a public image URL) to edit/restyle a source image while preserving its subjects — use modelId "nano-banana" for best identity/element preservation (e.g. keep a logo or face, redesign around it). Do NOT pass image models to generate_video. For end-user choice among candidates, prefer pick_reference_images. Scope required: generate:image.