Add Nix flake configuration

modules/security/pass.nix

@@ -0,0 +1,17 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+with lib.my;
+let cfg = config.modules.security.pass;
+in {
+  options.modules.security.pass = {
+    enable = mkBoolOpt false;
+  };
+
+  config = mkIf cfg.enable {
+    home.programs.password-store = {
+      enable = true;
+      package = pkgs.pass.withExtensions (exts: [ exts.pass-otp ]);
+    };
+  };
+}