How do I make a pin migrate back to its origin row when there is room?

reelSet.pin(reel, cell, id, { migration: 'origin', originCell }). 'origin' is already the default, so you only need originCell when the origin differs from the cell you are pinning. The pin clamps when the shape shrinks and climbs back toward originCell when it grows again. Use migration: 'frozen' for lock-and-never-restore.