docs(audit): align documentation with post-remediation backend reality

- Update data model enums to match backend models
- Update API reference auth requirements
- Add dispute module references and warning blocks
- Add 2026-05-24 audit remediation callout to Overview
- Generate task breakdowns and audit artifacts
- Add doc alignment report (.taskmaster/reports/)

Taskmaster/Tasks/task-2-3.md

@@ -0,0 +1,35 @@
+---
+taskmaster_id: "2.3"
+status: "done"
+priority: "high"
+depends_on: ["1"]
+parent_id: "2"
+source: "taskmaster"
+generated_at: "2026-05-24T07:15:25.199Z"
+---
+
+# 2.3 - Replace stubbed passkey/WebAuthn flow
+
+- [x] 2.3 - Replace stubbed passkey/WebAuthn flow #taskmaster #priority/high #status/done ⏫ 🆔 tm-2-3 ⛔ tm-1
+
+## Metadata
+
+| Field | Value |
+| --- | --- |
+| Taskmaster ID | 2.3 |
+| Status | done |
+| Priority | high |
+| Dependencies | 1 |
+| Parent | 2 - Implement platform audit remediation plan |
+
+## Description
+
+Implement production-grade WebAuthn registration/authentication and shared challenge storage.
+
+## Details
+
+Use real attestation/assertion verification, Redis-backed TTL challenges, refresh-token persistence/rotation, and deterministic malformed/reused/expired challenge errors.
+
+## Verification
+
+Registration, login, replay, expired challenge, and refresh-token continuity tests pass.