- "save IMAGE to file" and "save IMAGE+MASK to file": `format` is now a dropdown
(still connectable as a STRING) whose entries are derived from the formats the
installed Pillow/image plugins can actually write (RGB node offers them all,
IMAGE+MASK only alpha-capable ones); every batch frame is written instead of
only the first; and `path` can be switched to ComfyUI-style `filename_prefix`
mode via a toggle, resolved through ComfyUI's own folder/file helpers
(auto-numbered under the output dir); both modes accept ComfyUI templates such
as `%date:yyyy-MM-dd%`