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/_setCacheAdd.js

@@ -0,0 +1,19 @@
+/** Used to stand-in for `undefined` hash values. */
+var HASH_UNDEFINED = '__lodash_hash_undefined__';
+
+/**
+ * Adds `value` to the array cache.
+ *
+ * @private
+ * @name add
+ * @memberOf SetCache
+ * @alias push
+ * @param {*} value The value to cache.
+ * @returns {Object} Returns the cache instance.
+ */
+function setCacheAdd(value) {
+  this.__data__.set(value, HASH_UNDEFINED);
+  return this;
+}
+
+module.exports = setCacheAdd;