refactor(flake-parts): initial flake-parts configuration

inputs/system/modules/base/nix/nixpkgs/default.nix

@@ -0,0 +1,26 @@
+{ lib, config, inputs, ... }:
+
+let
+  inherit (lib) mkIf;
+  host = config.systemModules.host;
+in
+
+{
+  config = mkIf (host.type != "phone") {
+    nixpkgs = {
+      config = {
+        allowUnfree = true;
+        permittedInsecurePackages = [
+          "openssl-1.1.1u"
+          "electron-25.9.0"
+        ];
+      };
+      overlays = [
+        (final: prev: {
+          waybar = inputs.nixpkgs-wayland.packages.${prev.system}.waybar;
+          zjstatus = inputs.zjstatus.packages.${prev.system}.default;
+        })
+      ];
+    };
+  };
+}