- Added asynchronous Kitty conversion for assistant tool images using `convertToPng`, keyed per tool-call entry with cached and in-flight tracking.
- Updated assistant image rendering to prefer converted PNGs for Kitty terminals while preserving existing behavior for other protocols.
- Added a unit test that verifies WebP tool images are converted and rendered as Kitty image output instead of the raw image/webp fallback.
can1357