Website restoration: Node.js backend, restored design, GitHub sync disabled

- Replaced broken .NET backend with Node.js/Express
- Restored original website design with purple gradient hero
- Updated homepage and shop pages with Bootstrap 5 responsive design
- Disabled GitHub remote sync - all code now stored locally only
- Created backup scripts and documentation
- All changes saved on Ubuntu server at /var/www/SkyArtShop

backend/node_modules/lodash/flake.nix

@@ -0,0 +1,20 @@
+{
+  inputs = {
+    utils.url = "github:numtide/flake-utils";
+  };
+
+  outputs = { self, nixpkgs, utils }:
+    utils.lib.eachDefaultSystem (system:
+      let
+        pkgs = nixpkgs.legacyPackages."${system}";
+      in rec {
+       devShell = pkgs.mkShell {
+          nativeBuildInputs = with pkgs; [
+            yarn
+            nodejs-14_x
+            nodePackages.typescript-language-server
+            nodePackages.eslint
+          ];
+        };
+      });
+}