feat(frontend): add API client, layout, and routing

- Create Axios-based API client with sources, jobs, and dashboard endpoints
- Add responsive Layout component with navigation sidebar
- Set up React Router with Dashboard, Backups, and Settings routes
- Configure TanStack Query provider with default options
- Use lucide-react for navigation icons

frontend/node_modules/lodash/thru.js

@@ -0,0 +1,28 @@
+/**
+ * This method is like `_.tap` except that it returns the result of `interceptor`.
+ * The purpose of this method is to "pass thru" values replacing intermediate
+ * results in a method chain sequence.
+ *
+ * @static
+ * @memberOf _
+ * @since 3.0.0
+ * @category Seq
+ * @param {*} value The value to provide to `interceptor`.
+ * @param {Function} interceptor The function to invoke.
+ * @returns {*} Returns the result of `interceptor`.
+ * @example
+ *
+ * _('  abc  ')
+ *  .chain()
+ *  .trim()
+ *  .thru(function(value) {
+ *    return [value];
+ *  })
+ *  .value();
+ * // => ['abc']
+ */
+function thru(value, interceptor) {
+  return interceptor(value);
+}
+
+module.exports = thru;