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/mean.js

@@ -0,0 +1,22 @@
+var baseMean = require('./_baseMean'),
+    identity = require('./identity');
+
+/**
+ * Computes the mean of the values in `array`.
+ *
+ * @static
+ * @memberOf _
+ * @since 4.0.0
+ * @category Math
+ * @param {Array} array The array to iterate over.
+ * @returns {number} Returns the mean.
+ * @example
+ *
+ * _.mean([4, 2, 8, 6]);
+ * // => 5
+ */
+function mean(array) {
+  return baseMean(array, identity);
+}
+
+module.exports = mean;