- "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%`
Extended functionality to load and save strings, RGB/RGBA images, and masks, with various format options and error handling. Updated tests to cover new capabilities, ensuring robust behavior across different use cases. Updated documentation and version to reflect these changes.