The window's straddle commands hold more than the turn they open and
close: the opener carries the previous wizard's last draws, the closer
the next wizard's first upkeep — so every instant replay ran on into
the following turn (and, with the camera now following the turn-taker,
jumped into the next wizard's head for the overrun). momentSteps trims
both straddles at the boundary events: the reel opens on "X's turn
begins" and stops at X's turnEnded, keeping only what belongs to X.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>