Pick the output format for generated images

output.format on POST /image/generate now decides the encoding. Pass png, jpg, or webp and Mynth converts the image before delivering it. Leave it out and you get whatever the provider returned.

{
  "model": "black-forest-labs/flux.2-pro",
  "prompt": "A futuristic cityscape at sunset with flying cars",
  "output": { "format": "webp" }
}

Every successful image in the result now carries a format field, so you can read what was actually delivered instead of inferring it from the URL.

Two fields went away. output.quality is gone, and each format encodes at its own default. Per-image cost is gone from the result as well, so read the task-level cost instead.

Results also report magic_prompt again when magic prompt rewrites your prompt. It had been dropped from the payload.