Windows/WSL: 8.3 short-name path components now treated as protected

Windows can give files and folders an old-style short name, such as PROGRA~1, in what is called the 8.3 format. On Windows and on WSL (Windows Subsystem for Linux, which runs Linux inside Windows), Claude Code's protected-path check now flags any part of a path that looks like one of these short names. A protected path is one Claude Code treats with extra care before touching. An older check that ran only on WSL was removed from this part of the test.