Warn when the info API's windows pipe is outside the protected namespace

A program reading the info API opens the pipe by name and has no owner
check of its own, so for a name any local user could create first,
whoever did would be answering its queries. nebula refuses to serve a
held name and logs it, but the program cannot tell. The daemon now warns
at bind when the configured name is not under
\\.\pipe\ProtectedPrefix\Administrators\, and the example config and
CHANGELOG say to put it there.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

localapi/info.go

@@ -127,6 +127,9 @@ func (s *InfoServer) Rebind(ctx context.Context, path string, acc Access) error
 		}
 
 		s.l.Info("Local info API listening", "path", path, "access", acc.String())
+		if w := unprotectedNameWarning(path); w != "" {
+			s.l.Warn("Local info API is served on a pipe name that is not protected", "path", path, "risk", w)
+		}
 		go s.serve(srv, ln)
 
 		// Closing the server closes the listener Serve was handed, and a Serve that has