Recursive delete now refuses permission denials up front — never half-deletes a subtree

Deleting a folder tree you were not fully allowed to delete could previously remove part of the tree before stopping: the permission check for each node ran while the deletion was already underway, so dozens of nodes could be gone by the time the denial hit — and the error was reported as an unexpected failure rather than a permission problem.

Recursive deletes now decide permissions for the whole subtree before touching anything. If you lack Delete on any node in the tree, nothing is deleted and you get a clear message naming the node you are not allowed to delete. A delete that was fully authorized when it started can also no longer trip over its own access records mid-way — it either refuses up front or completes fully.