vfs.readdir()'s ReaddirOptions.recursive was typed but silently ignored: a
recursive request behaved identically to a non-recursive one. Implemented
properly: recursive listing walks every descendant (files and directories,
any depth) via the same graph-traversal + one-batch-fetch path
getTreeStructure()/getDescendants() already use, and reports each entry as
a path relative to the queried directory (Node's fs.readdir(dir,
{ recursive: true }) convention) — 'sub/file.txt', not just 'file.txt'.
With withFileTypes: true, each VFSDirent.name carries that same relative
path when recursive (matching the string-array form byte for byte);
VFSDirent.path stays the absolute VFS path either way, so no information is
lost. Filter/sort/pagination compose unchanged, now over the full recursive
set. Non-recursive behavior (direct children, named by basename) is
unchanged.
