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-admin-v2/node_modules/fs-constants/README.md

@@ -0,0 +1,26 @@
+# fs-constants
+
+Small module that allows you to get the fs constants across
+Node and the browser. 
+
+```
+npm install fs-constants
+```
+
+Previously you would use `require('constants')` for this in node but that has been
+deprecated and changed to `require('fs').constants` which does not browserify.
+
+This module uses `require('constants')` in the browser and `require('fs').constants` in node to work around this
+
+
+## Usage
+
+``` js
+var constants = require('fs-constants')
+
+console.log('constants:', constants)
+```
+
+## License
+
+MIT