Add jujutsu config

modules/common/jujutsu.nix

@@ -0,0 +1,38 @@
+{ config, lib, pkgs, ... }: let
+  inherit (lib) enabled getExe;
+in {
+  environment.systemPackages = [
+    pkgs.difftastic
+  ];
+
+  home-manager.sharedModules = [(homeArgs: let
+    homeConfig = homeArgs.config;
+    homeLib    = homeArgs.config.lib;
+  in {
+    # HACK: There is no way to get libgit2 to use custom key paths so we are linking this.
+    home.file.".ssh/id_ed25519".source = homeLib.file.mkOutOfStoreSymlink "${homeConfig.home.homeDirectory}/.ssh/id";
+
+    programs.jujutsu = enabled {
+      settings = let
+        # TODO: mailDomain = head self.disk.mailserver.domains;
+        mailDomain = "rgbcu.be";
+      in {
+        user.name  = "RGBCube";
+        user.email = "git@${mailDomain}";
+
+        ui.default-command = "log";
+        ui.diff            = [ "${getExe pkgs.difftastic}" "--color" "always" "$left" "$right" ];
+
+        ui.conflict-marker-style = "snapshot";
+        ui.graph.style = if config.theme.cornerRadius > 0 then "curved" else "square";
+
+        git.auto-local-bookmark  = true;
+        git.push-bookmark-prefix = "change-";
+
+        signing.sign-all = true;
+        signing.backend  = "ssh";
+        signing.key     = "~/.ssh/id";
+      };
+    };
+  })];
+}