The broom is this sprint's gate and B's spec says the two lanes meet in the
middle. Posting the shape now rather than at the end so B can land it while I
build against it: ponds[] with a live world pos (I have to walk under the
belly), and drainPondAt returning the kg dumped (that number decides splash vs
stagger vs flat on your back).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>