set up ssh signing

modules/other/default.nix

@@ -1 +1 @@
-_: {imports = [./home-manager.nix ./system.nix ./xdg.nix];}
+_: {imports = [./home-manager.nix ./system.nix ./xdg.nix ./git.nix];}

modules/other/git.nix

@@ -0,0 +1,13 @@
+{config, ...}: let
+  inherit (config.modules.other.system) username;
+in {
+  home-manager.users.${username} = {
+    programs.git = {
+      signing = {
+        key = "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAILPiRe9OH/VtWFWyy5QbAVcN7CLxr4zUtRCwmxD6aeN6";
+        signByDefault = true;
+      };
+      extraConfig.gpg.format = "ssh";
+    };
+  };
+}

modules/other/system.nix

@@ -30,9 +30,5 @@ in {
       isNormalUser = true;
       extraGroups = ["wheel"];
     };
-    users.users.test = {
-      isNormalUser = true;
-      extraGroups = ["wheel"];
-    };
   };
 }