message: Always elevate 1000 in `zIndex` when node is selected
  Instead of only elevating when `zIndex` is unset
diff: @@ -39,7 +39,7 @@ export function createNodeInternals(nodes: Node[], nodeInternals: NodeInternals)
  const parentNodes: ParentNodes = {};
  nodes.forEach((node) => {
  - const z = isNumeric(node.zIndex) ? node.zIndex : node.selected ? 1000 : 0;
  + const z = (isNumeric(node.zIndex) ? node.zIndex : 0) + (node.selected ? 1000 : 0);
  const currInternals = nodeInternals.get(node.id);
  const internals: Node = {
  