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/_SetCache.js

@@ -0,0 +1,27 @@
+var MapCache = require('./_MapCache'),
+    setCacheAdd = require('./_setCacheAdd'),
+    setCacheHas = require('./_setCacheHas');
+
+/**
+ *
+ * Creates an array cache object to store unique values.
+ *
+ * @private
+ * @constructor
+ * @param {Array} [values] The values to cache.
+ */
+function SetCache(values) {
+  var index = -1,
+      length = values == null ? 0 : values.length;
+
+  this.__data__ = new MapCache;
+  while (++index < length) {
+    this.add(values[index]);
+  }
+}
+
+// Add methods to `SetCache`.
+SetCache.prototype.add = SetCache.prototype.push = setCacheAdd;
+SetCache.prototype.has = setCacheHas;
+
+module.exports = SetCache;