NodePath
A stable, structural identity for a node within the resolved tree.
The path encodes the node's position as a dash-joined chain of child indices descending from the root (e.g. "0-1-0" is the first child of the second child of the root). Because it is derived purely from tree position, it stays stable across re-resolves of the same document and is suitable as a key (for example for Compose key/remember). Carried by ResolvedNode.path.