Interop vs Display

• Interop (AsRef): use interop_path() on StrictPath, VirtualPath, PathBoundary, and VirtualRoot. It borrows the underlying OS path without allocations.
• Display to users:
  • System paths: use strictpath_display() (on StrictPath/PathBoundary).
  • Virtual UI paths: use virtualpath_display() (on VirtualPath).
• Never use interop_path().to_string_lossy() for display—mixes concerns and may leak internals.
• Do not wrap secure types with Path::new or PathBuf::from.
• Directory discovery vs validation:
  • Discover children via read_dir(root.interop_path()) or root helpers.
  • Re-validate names with strict_join()/virtual_join() before any I/O.