kanidm-client: use short names instead of SPN format

Configure uid_attr_map and gid_attr_map to "name" to return short
usernames (torjus) instead of SPN format (torjus@home.2rjus.net).
This fixes "PAM user mismatch" errors with SSH authentication.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

system/kanidm-client.nix

@@ -30,6 +30,10 @@ in
 
       unixSettings = {
         pam_allowed_login_groups = cfg.allowedLoginGroups;
+        # Use short names (torjus) instead of SPN format (torjus@home.2rjus.net)
+        # This prevents "PAM user mismatch" errors with SSH
+        uid_attr_map = "name";
+        gid_attr_map = "name";
       };
     };
   };