refactor: archive old features directory to features.old

The new profile-based structure (home/base, home/desktop, home/server,
home/profiles/, home/coding) is fully operational and imported via
home/lib/mkHomeConfig. The legacy home/features directory is no longer
referenced anywhere in the configuration.

Archived rather than deleted to preserve history for reference.

home/features.old/cli/secrets.nix

@@ -0,0 +1,22 @@
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
+with lib; let
+  cfg = config.features.cli.secrets;
+in {
+  options.features.cli.secrets.enable = mkEnableOption "enable secrets";
+
+  config = mkIf cfg.enable {
+    programs.password-store = {
+      enable = true;
+      package =
+        pkgs.pass-wayland.withExtensions
+        (exts: [exts.pass-otp exts.pass-import]);
+      settings = {PASSWORD_STORE_DIR = "$XDG_DATA_HOME/password-store";};
+    };
+    home.packages = with pkgs; [pinentry-gnome3];
+  };
+}