The delta was this frame's position minus the last, and the last started at 0,0, so the
first frame reported the cursor's whole distance from the corner as motion. A cursor-mode
change did the same, switching between a locked cursor's virtual reticle and the real
cursor. Maroon Lake's camera adds mouse_dy to its pitch and came up pointing at the ground.
examples/library/input_mouse_rebase.ludic covers both cases, plus ordinary motion and
re-setting the mode already in force.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
