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/)

04 - Flows/Escrow Flow.md

@@ -19,7 +19,7 @@ The escrow is not a separate smart contract — it is a **state machine on the `
 
 ## Escrow state machine (`Payment.escrowState`)
 
-Enum from `Payment.ts:112-115`: `funded | releasable | released | refunded | releasing | failed`.
+Enum from `Payment.ts:112-115`: `funded | releasable | released | refunded | releasing | failed | cancelled | partial`.
 
 ```mermaid
 stateDiagram-v2
@@ -33,9 +33,12 @@ stateDiagram-v2
     Releasing --> Failed: payout tx reverted\nescrowState="failed"
     Funded --> Refunded: dispute resolution = refund\nescrowState="refunded"
     Funded --> Refunded: order cancelled\npre-shipment
+    Pending --> Cancelled: webhook EXPIRED/CANCELLED
+escrowState="cancelled"
     Failed --> Releasing: admin retries
     Released --> [*]
     Refunded --> [*]
+    Cancelled --> [*]
 ```
 
 `Payment.status` mirrors a coarser business state: