refactor

modules/capabilities/git.nix

@@ -18,7 +18,8 @@ in
           email = account.emails.${scope}.address;
           key = machine.sshKeys.${scope} or null;
           hasSigningKey = key != null;
-          privateKeyPath = key.privateKeyPath or "~/.ssh/id_${scope}";
+          privateKeyPath =
+            if hasSigningKey && key.privateKeyPath != null then key.privateKeyPath else "~/.ssh/id_${scope}";
         in
         {
           allowedSigners = lib.optional hasSigningKey "${email} ${key.publicKey}";