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/cookie-signature/Readme.md

@@ -0,0 +1,23 @@
+
+# cookie-signature
+
+  Sign and unsign cookies.
+
+## Example
+
+```js
+var cookie = require('cookie-signature');
+
+var val = cookie.sign('hello', 'tobiiscool');
+val.should.equal('hello.DGDUkGlIkCzPz+C0B064FNgHdEjox7ch8tOBGslZ5QI');
+
+var val = cookie.sign('hello', 'tobiiscool');
+cookie.unsign(val, 'tobiiscool').should.equal('hello');
+cookie.unsign(val, 'luna').should.be.false;
+```
+
+## License
+
+MIT.
+
+See LICENSE file for details.