fix(workflow): ADR-021 code review fixes (8 bugs)

- fix(transmittal): guard duplicate workflow instance on submit()
- fix(workflow-guard): add organizationId to context so Level-2 RBAC works
- fix(circulation): organizationId context passed relation object not INT FK
- fix(transmittal): require Idempotency-Key header on POST submit endpoint
- fix(workflow): userId non-optional in processTransition controller
- fix(circulation): auto-close counts PENDING and IN_PROGRESS tasks
- fix(transmittal): status badge uses workflowState/DRAFT not purpose field
- fix(workflow): log cache invalidation failures instead of swallowing
- fix(workflow): implement getAvailableActions endpoint stub
- fix(i18n): add removeFile key to EN/TH locales

frontend/app/(dashboard)/transmittals/[uuid]/page.tsx

@@ -60,7 +60,9 @@ export default function TransmittalDetailPage() {
 
   const transmittalDocNo = transmittal.correspondence?.correspondenceNumber ?? transmittal.transmittalNo ?? '';
   const transmittalSubject = transmittal.subject ?? '';
-  const transmittalStatus = transmittal.purpose ?? '';
+  const transmittalStatus = transmittal.workflowInstanceId
+    ? (transmittal.workflowState ?? 'SUBMITTED')
+    : 'DRAFT';
 
   return (
     <section className="space-y-4">