Why isn't this a method on Entry?

   public Entry resolveChild(String path);

Which... isn't that just like getChild?  Except we accept a path here, not just a name, and we may incur a very expensive stat hit due to forking to compute a symlink on some systems, and getChild doesn't do that.

If you are trying to replace FS.resolve you really should also drag over the discussion in the method's Javadoc, like how expensive it is to execute, why this should be used over getChild(), why getChild should be used over resolve().  Etc.