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

node_modules/qs/.github/SECURITY.md

@@ -0,0 +1,11 @@
+# Security
+
+Please file a private vulnerability report via GitHub, email [@ljharb](https://github.com/ljharb), or see https://tidelift.com/security if you have a potential security vulnerability to report.
+
+## Incident Response Plan
+
+Please see our [Incident Response Plan](https://github.com/ljharb/.github/blob/main/INCIDENT_RESPONSE_PLAN.md).
+
+## Threat Model
+
+Please see [THREAT_MODEL.md](./THREAT_MODEL.md).