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/middleware/auth.js

@@ -0,0 +1,28 @@
+const requireAuth = (req, res, next) => {
+  if (req.session && req.session.adminId) {
+    return next();
+  }
+  res.redirect('/admin/login');
+};
+
+const requireRole = (allowedRoles) => {
+  return (req, res, next) => {
+    if (!req.session || !req.session.adminId) {
+      return res.redirect('/admin/login');
+    }
+    const userRole = req.session.role || 'user';
+    if (allowedRoles.includes(userRole)) {
+      return next();
+    }
+    res.status(403).send('Access denied');
+  };
+};
+
+const redirectIfAuth = (req, res, next) => {
+  if (req.session && req.session.adminId) {
+    return res.redirect('/admin/dashboard');
+  }
+  next();
+};
+
+module.exports = { requireAuth, requireRole, redirectIfAuth };