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-4.md

@@ -0,0 +1,35 @@
+---
+taskmaster_id: "4"
+status: "in-progress"
+priority: "high"
+depends_on: []
+parent_id: ""
+source: "taskmaster"
+generated_at: "2026-05-24T07:15:25.199Z"
+---
+
+# 4 - Define backend security and refactor strategy from latest audit
+
+- [ ] 4 - Define backend security and refactor strategy from latest audit #taskmaster #priority/high #status/in-progress ⏫ 🆔 tm-4
+
+## Metadata
+
+| Field | Value |
+| --- | --- |
+| Taskmaster ID | 4 |
+| Status | in-progress |
+| Priority | high |
+| Dependencies | None |
+| Parent | None |
+
+## Description
+
+Convert the backend stack security/refactor assessment into concrete architecture decisions, documentation deliverables, and developer handoff criteria.
+
+## Details
+
+Source audit: .taskmaster/docs/audit-backend-stack-security-and-refactor-assessment-2026-05-24.md. This task is advisory/architecture-focused and should run in parallel with immediate hardening. It should produce the decision artifacts needed before any backend-core rewrite or provider migration is started.
+
+## Verification
+
+Review and sign off each architecture document with backend, payments, frontend, and operations stakeholders. Confirm every open question has an owner or explicit deferred decision before implementation work begins.