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/jws/lib/data-stream.js

@@ -0,0 +1,55 @@
+/*global module, process*/
+var Buffer = require('safe-buffer').Buffer;
+var Stream = require('stream');
+var util = require('util');
+
+function DataStream(data) {
+  this.buffer = null;
+  this.writable = true;
+  this.readable = true;
+
+  // No input
+  if (!data) {
+    this.buffer = Buffer.alloc(0);
+    return this;
+  }
+
+  // Stream
+  if (typeof data.pipe === 'function') {
+    this.buffer = Buffer.alloc(0);
+    data.pipe(this);
+    return this;
+  }
+
+  // Buffer or String
+  // or Object (assumedly a passworded key)
+  if (data.length || typeof data === 'object') {
+    this.buffer = data;
+    this.writable = false;
+    process.nextTick(function () {
+      this.emit('end', data);
+      this.readable = false;
+      this.emit('close');
+    }.bind(this));
+    return this;
+  }
+
+  throw new TypeError('Unexpected data type ('+ typeof data + ')');
+}
+util.inherits(DataStream, Stream);
+
+DataStream.prototype.write = function write(data) {
+  this.buffer = Buffer.concat([this.buffer, Buffer.from(data)]);
+  this.emit('data', data);
+};
+
+DataStream.prototype.end = function end(data) {
+  if (data)
+    this.write(data);
+  this.emit('end', data);
+  this.emit('close');
+  this.writable = false;
+  this.readable = false;
+};
+
+module.exports = DataStream;