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/defaultTo.js

@@ -0,0 +1,25 @@
+/**
+ * Checks `value` to determine whether a default value should be returned in
+ * its place. The `defaultValue` is returned if `value` is `NaN`, `null`,
+ * or `undefined`.
+ *
+ * @static
+ * @memberOf _
+ * @since 4.14.0
+ * @category Util
+ * @param {*} value The value to check.
+ * @param {*} defaultValue The default value.
+ * @returns {*} Returns the resolved value.
+ * @example
+ *
+ * _.defaultTo(1, 10);
+ * // => 1
+ *
+ * _.defaultTo(undefined, 10);
+ * // => 10
+ */
+function defaultTo(value, defaultValue) {
+  return (value == null || value !== value) ? defaultValue : value;
+}
+
+module.exports = defaultTo;