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/jsonwebtoken/lib/timespan.js

@@ -0,0 +1,18 @@
+var ms = require('ms');
+
+module.exports = function (time, iat) {
+  var timestamp = iat || Math.floor(Date.now() / 1000);
+
+  if (typeof time === 'string') {
+    var milliseconds = ms(time);
+    if (typeof milliseconds === 'undefined') {
+      return;
+    }
+    return Math.floor(timestamp + milliseconds / 1000);
+  } else if (typeof time === 'number') {
+    return timestamp + time;
+  } else {
+    return;
+  }
+
+};