[yubikey] Add module

nixos/modules/hardware/default.nix

@@ -1,5 +1,6 @@
 {
   imports = [
     ./nvidia
+    ./yubikey
   ];
 }

nixos/modules/hardware/yubikey/default.nix

@@ -0,0 +1,17 @@
+{ config, lib, pkgs, ... }:
+
+let
+  cfg = config.sisyphus.hardware.yubikey;
+in {
+  options.sisyphus.hardware.yubikey.enable = lib.mkEnableOption "YubiKey support";
+
+  config = lib.mkIf cfg.enable {
+    # Enable smart card reading
+    services.pcscd.enable = true;
+
+    programs.gnupg.agent = {
+      enable = true;
+      pinentryFlavor = "curses";
+    };
+  };
+}