integrate gsf via flake input and hardware.gsf module

modules/hosts/nixos.nix

@@ -14,10 +14,13 @@ in {
   }: let
     smbSecretFile = ../../secrets/smb-credentials.age;
     hasSmbSecret = builtins.pathExists smbSecretFile;
+
+    gsfDevice = "/dev/input/by-id/usb-Ploopy_Corporation_Ploopy_Adept_Trackball_E6626067D39C532A0000000000000000-if02-event-mouse";
   in {
     imports = [
       inputs.agenix.nixosModules.default
       inputs.maccel.nixosModules.default
+      inputs.gsf.nixosModules.default
       ../../hardware-configuration.nix
     ];
 
@@ -102,18 +105,10 @@ in {
       enableCli = true;
     };
 
-    # Dotfile-managed maccel settings: place an executable script at
-    # ~/.config/maccel/apply.sh with your preferred `maccel set ...` commands.
-    systemd.user.services.maccel-apply-dotfiles = {
-      description = "apply maccel params from ~/.config/maccel/apply.sh";
-      wantedBy = ["default.target"];
-      after = ["default.target"];
-      serviceConfig = {
-        Type = "oneshot";
-        ExecStart = ''
-          ${pkgs.bash}/bin/bash -lc 'PATH=/run/current-system/sw/bin:$PATH; if [ -x "$HOME/.config/maccel/apply.sh" ]; then "$HOME/.config/maccel/apply.sh"; fi'
-        '';
-      };
+    hardware.gsf = {
+      enable = true;
+      device = gsfDevice;
+      inputGroupUsers = [flakeConfig.username];
     };
 
     # Programs