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-api/node_modules/pg-protocol/dist/buffer-writer.d.ts

@@ -0,0 +1,17 @@
+export declare class Writer {
+    private size;
+    private buffer;
+    private offset;
+    private headerPosition;
+    constructor(size?: number);
+    private ensure;
+    addInt32(num: number): Writer;
+    addInt16(num: number): Writer;
+    addCString(string: string): Writer;
+    addString(string?: string): Writer;
+    addInt32PrefixedString(string: string): Writer;
+    add(otherBuffer: Buffer): Writer;
+    private join;
+    flush(code?: number): Buffer;
+    clear(): void;
+}