arti CLI is not reporting hints

If you try to start Arti with a directory having bad permissions, you get output like this:

[1027]$ ./target/quicktest/arti proxy -c cfgs/plain.toml
./target/quicktest/arti: error: Incorrect permissions: ${HOME}/arti_hax is u=rwx,g=rwx,o=rwx; must be o-w
[1028]$ 

Notably, this does not include the output of arti_client::Error::hint(), which would have included a (hopefully) much more useful message, something like

 Permissions are set too permissively on ${HOME}/arti_hax: currently u=rwx,g=rwx,o=rw.
  * Untrusted users could modify its contents and override our behavior.
  * Untrusted users could read its contents.
 You can fix this by further restricting the permissions of your filesystem, using:
  chmod og-rwx  ${HOME}/arti_hax
 You can suppress this message by setting storage.permissions.dangerously_trust_everyone=true,
 or setting ARTI_FS_DISABLE_PERMISSION_CHECKS=yes in your environment.

We should actually display these messages!