Adds a dropdown to the Builder UI's Run Settings section letting users pick the saved image file format. Default remains webp (current behavior). State plumbed through state_to_configs_json -> _session_settings -> orchestrator -> save_image_to_disk. PNG users will see lossless saves; JPG users smaller files at quality 95. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>