feat: Passwordless cross-device authentication

- Arkitektur: docs/auth/passwordless-architecture.md
- Backend: iom/quixzoom-auth-service/ (FastAPI + Redis)
- Webb: quixzoom-market-pages/se/login/ (QR-kod + polling)
- App: iom/quixzoom-app/src/features/auth/ (push + deep links)

Flöde: QR-kod → app-godkännande → webb-inloggad

landvex/node_modules/lodash/head.js

@@ -0,0 +1,23 @@
+/**
+ * Gets the first element of `array`.
+ *
+ * @static
+ * @memberOf _
+ * @since 0.1.0
+ * @alias first
+ * @category Array
+ * @param {Array} array The array to query.
+ * @returns {*} Returns the first element of `array`.
+ * @example
+ *
+ * _.head([1, 2, 3]);
+ * // => 1
+ *
+ * _.head([]);
+ * // => undefined
+ */
+function head(array) {
+  return (array && array.length) ? array[0] : undefined;
+}
+
+module.exports = head;