create xmodmap-arrow config

hosts/citadel/default.nix

@@ -1,25 +1,39 @@
-{ inputs, lib, pkgs, config, ... }:
-let
+{
+  inputs,
+  lib,
+  pkgs,
+  config,
+  ...
+}: let
   # Disko setup
   fsType = "btrfs"; # one of ext4 or btrfs. Use btrfs if using impermanence
   dev = "/dev/nvme0n1"; # depends on target hardware
   encrypted = true; # currrently only applies to btrfs
-  btrfsMountDevice = if encrypted then "/dev/mapper/crypted" else "/dev/root_vg/root";
+  btrfsMountDevice =
+    if encrypted
+    then "/dev/mapper/crypted"
+    else "/dev/root_vg/root";
   user = "sam";
   impermanence = true;
-in
-{
-  imports =
-    [
+in {
+  imports = [
     # Create users for this host
     ../common/users/${user}
 
     # Disk configuration
     inputs.disko.nixosModules.disko
-      (import ../common/disks { device = dev; impermanence = impermanence; fsType = fsType; encrypted = encrypted; })
+    (import ../common/disks {
+      device = dev;
+      impermanence = impermanence;
+      fsType = fsType;
+      encrypted = encrypted;
+    })
 
     # Impermanence
-      (import ../common/disks/btrfs/impermanence.nix { btrfsMountDevice = btrfsMountDevice; lib = lib; })
+    (import ../common/disks/btrfs/impermanence.nix {
+      btrfsMountDevice = btrfsMountDevice;
+      lib = lib;
+    })
 
     # Import core options
     ./hardware-configuration.nix
@@ -35,7 +49,7 @@ in
     ../common/optional/nfs-mounts/photos.nix
     ../common/optional/printing.nix
     ../common/optional/backlight.nix
-
+    ../common/optional/xmodmap-arrow-remaps.nix
   ];
 
   boot = {
@@ -81,16 +95,6 @@ in
     };
   };
 
-  # Remap Alt_L +[hjkl] to left down up right
-  services.xserver.displayManager.sessionCommands =
-    "${pkgs.xorg.xmodmap}/bin/xmodmap ${pkgs.writeText  "xkb-layout" ''
-      keycode 64 = Mode_switch
-      keycode 43 = h H Left H
-      keycode 44 = j J Down J
-      keycode 45 = k K Up K
-      keycode 46 = l L Right L
-  ''}";
-
   hardware = {
     bluetooth = {
       enable = true;

hosts/common/optional/xmodmap-arrow-remaps.nix

@@ -0,0 +1,12 @@
+{pkgs, ...}: let
+  customLayout = pkgs.writeText "xkb-layout" ''
+    keycode 64 = Mode_switch
+    keycode 43 = h H Left H
+    keycode 44 = j J Down J
+    keycode 45 = k K Up K
+    keycode 46 = l L Right L
+  '';
+in {
+  # Remap Alt_L +[hjkl] to left down up right
+  services.xserver.displayManager.sessionCommands = "sleep 5 && ${pkgs.xorg.xmodmap}/bin/xmodmap ${customLayout}";
+}