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/_baseAssignIn.js

@@ -0,0 +1,17 @@
+var copyObject = require('./_copyObject'),
+    keysIn = require('./keysIn');
+
+/**
+ * The base implementation of `_.assignIn` without support for multiple sources
+ * or `customizer` functions.
+ *
+ * @private
+ * @param {Object} object The destination object.
+ * @param {Object} source The source object.
+ * @returns {Object} Returns `object`.
+ */
+function baseAssignIn(object, source) {
+  return object && copyObject(source, keysIn(source), object);
+}
+
+module.exports = baseAssignIn;