moveChild
Moves an existing direct child to a new position within this node's children.
toIndex is coerced into the valid range, so out-of-range targets clamp to the first or last position. Because child is already a direct child, no re-parenting or cycle check is needed.
Return
true if child was a direct child and has been moved; false otherwise.
Parameters
child
the node to reorder; must already be a direct child of this node.
toIndex
the target position for child after removal, coerced into 0..children.size.