feat(nixpak): exp. nixpak

nixcfgs/hardening/nixpaks/default.nix

@@ -0,0 +1,21 @@
+{
+  pkgs,
+  inputs,
+  ...
+}:
+let
+  mkNixPak = inputs.nixpak.lib.nixpak {
+    inherit (pkgs) lib;
+    inherit pkgs;
+  };
+in
+{
+  # Expose sandboxed app(s) through nixpkgs overlay.
+  nixpkgs.overlays = [
+    (_: prev: {
+      nixpaks.qq = prev.callPackage ./qq.nix {
+        inherit mkNixPak;
+      };
+    })
+  ];
+}