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-master-api/node_modules/pg-protocol/src/buffer-reader.ts

@@ -0,0 +1,58 @@
+export class BufferReader {
+  private buffer: Buffer = Buffer.allocUnsafe(0)
+
+  // TODO(bmc): support non-utf8 encoding?
+  private encoding: BufferEncoding = 'utf-8'
+
+  constructor(private offset: number = 0) {}
+
+  public setBuffer(offset: number, buffer: Buffer): void {
+    this.offset = offset
+    this.buffer = buffer
+  }
+
+  public int16(): number {
+    const result = this.buffer.readInt16BE(this.offset)
+    this.offset += 2
+    return result
+  }
+
+  public byte(): number {
+    const result = this.buffer[this.offset]
+    this.offset++
+    return result
+  }
+
+  public int32(): number {
+    const result = this.buffer.readInt32BE(this.offset)
+    this.offset += 4
+    return result
+  }
+
+  public uint32(): number {
+    const result = this.buffer.readUInt32BE(this.offset)
+    this.offset += 4
+    return result
+  }
+
+  public string(length: number): string {
+    const result = this.buffer.toString(this.encoding, this.offset, this.offset + length)
+    this.offset += length
+    return result
+  }
+
+  public cstring(): string {
+    const start = this.offset
+    let end = start
+    // eslint-disable-next-line no-empty
+    while (this.buffer[end++]) {}
+    this.offset = end
+    return this.buffer.toString(this.encoding, start, end - 1)
+  }
+
+  public bytes(length: number): Buffer {
+    const result = this.buffer.slice(this.offset, this.offset + length)
+    this.offset += length
+    return result
+  }
+}