Both page.OnAfterRenderAsync(firstRender=true) and
TreeView.OnAfterRenderAsync(firstRender=true) ran concurrently:
- Page called RevealNode → added ancestor keys to _expandedKeys
- TreeView awaited treeviewStorage.load → replaced _expandedKeys with
the persisted set (often empty if user collapsed before navigating)
Whichever JS interop completed second won. When TreeView won, the deep-link
reveal silently lost. Gate the reveal on firstRender==false so it runs
strictly after TreeView's restore is done.