Discovery from the home directory walked into ~/Library, where readdir on
TCC-protected group containers blocks forever for a daemon that cannot show
a consent prompt. Each blocked call holds a libuv threadpool thread, so a few
searches wedged every fs operation in the daemon.
- Add an excludedDiscoveryPaths option; discovery skips those paths, while
exact typed paths still resolve and browsing inside lists one level.
- Resolve rooted typed paths directly and anchor the walk under an existing
typed parent instead of walking the whole home directory.
Refs #4879
