Reorder Siblings

# Create ordered items
item_1 = uuid4()
item_2 = uuid4()
item_3 = uuid4()

tree.register_node(item_1)  # position 0
tree.register_node(item_2)  # position 1
tree.register_node(item_3)  # position 2

# Reorder: put item_3 first
tree.reorder_siblings(None, [item_3, item_1, item_2])

# Verify new order
roots = tree.get_roots()
print([r.id for r in roots])  # [item_3, item_1, item_2]