On macOS, /var is a symlink to /private/var. When New() stores the
unresolved root but validatePath() resolves child paths via EvalSymlinks,
the mismatch causes filepath.Rel to produce ".." prefixes — triggering
false SECURITY sandbox escape warnings on every file operation.
Fix: resolve symlinks on the root path in New() so both sides compare
like-for-like. Updates TestNew to compare against resolved paths.
Co-Authored-By: Virgil <virgil@lethean.io>