v0.1.48

history: every step is reported, so fizzy knows who made it (#57)

pixi called `Host.recordStep` only while something recorded the sprite, so
fizzy never kept who made a pixi step: undo couldn't name an agent's draw,
and `fizzy.undo` answered "the person" for it. Every step is now reported,
with the step on top (`Step.top`); its effect is still encoded only while
recording. Text already works this way.

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>