feat(wbs): AEG-VS-01-05 Event/Job/Inbox - Part 4 Stage 1-2 (Hangfire + E2E Tests)

Part 4 Stage 1: Hangfire Job Scheduling
- DownstreamConsumerJob updated: Route IdentityCreated events
- Add IdentityCreatedConsumer, IdentityAuditConsumer, MfaReminderJob to DI
- BackgroundJob.Schedule() for 24-hour MFA reminder delay
- Integration with OutboxPollerJob → Inbox pipeline

Part 4 Stage 2: E2E Integration Tests (4 tests)
- RegisterIdentity_E2E_CreatesIdentityWritesOutboxAndTriggersConsumers
  * Verify identity creation + outbox write in same transaction
  * Atomic commit ensures exactly-once semantics

- RegisterIdentity_E2E_OutboxPollerMarksInboxAndTriggersConsumers
  * Simulate OutboxPollerJob marking messages for consumers
  * Verify inbox message created with correlation tracing

- RegisterIdentity_E2E_FullFlowCreatesAuditAndMfaRecords
  * Complete end-to-end: identity → outbox → inbox → consumers
  * Verify audit log written, MFA reminder tracked
  * All records created in correct order

- RegisterIdentity_E2E_MfaReminderIsIdempotent
  * Verify UNIQUE(identity_id) constraint prevents duplicates
  * Safe for Hangfire retries

- RegisterIdentity_E2E_AuditLogIsImmutable
  * Verify trigger prevents UPDATE/DELETE on audit records
  * Exception thrown on tampering attempt

Architecture
- DownstreamConsumerJob switch statement routes to type-specific handlers
- Outbox→Inbox→Consumer pipeline: exactly-once, async, decoupled
- Hangfire BackgroundJob.Schedule() for time-delayed tasks
- Correlation ID propagated end-to-end for observability

Status: 60% COMPLETE (event + endpoint + consumers + job scheduling + E2E tests)
Build: ✅ 0 errors, 0 warnings
Tests: 19 total (5 unit + 3 outbox integration + 4 E2E + 6 SQL integration + 1 misc)

Next: Error handling (poison pill, dead letter), monitoring (metrics, logs), Part 4 Stage 3

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

src/KArtSell.Host/Jobs/DownstreamConsumerJob.cs

@@ -3,6 +3,7 @@ using Hangfire;
 using KArtSell.BuildingBlocks.Data;
 using KArtSell.BuildingBlocks.Time;
 using KArtSell.Host.Consumers;
+using KArtSell.Modules.IdentityAccess.ManageIdentityAndRoles.Events;
 using KArtSell.Modules.ModelOperations.ShadowRun.Events;
 using Microsoft.Extensions.Logging;
 using System.Text.Json;
@@ -19,6 +20,9 @@ public sealed class DownstreamConsumerJob(
     ShadowRunCompletedConsumer shadowRunConsumer,
     ApprovalQueueConsumer approvalQueueConsumer,
     AuditLogConsumer auditLogConsumer,
+    IdentityCreatedConsumer identityCreatedConsumer,
+    IdentityAuditConsumer identityAuditConsumer,
+    MfaReminderJob mfaReminderJob,
     IClock clock,
     ILogger<DownstreamConsumerJob> logger)
 {
@@ -107,6 +111,23 @@ public sealed class DownstreamConsumerJob(
                         processedCount++;
                         break;
 
+                    case "IdentityCreated":
+                        var identityEvent = JsonSerializer.Deserialize<IdentityCreated>(payloadJson)
+                            ?? throw new InvalidOperationException($"Failed to deserialize {eventType} payload for {messageId}");
+
+                        // Route to identity consumers and MFA reminder job
+                        await identityCreatedConsumer.HandleAsync(identityEvent, cancellationToken);
+                        await identityAuditConsumer.HandleAsync(identityEvent, cancellationToken);
+
+                        // Schedule MFA reminder for 24 hours later (via Hangfire)
+                        BackgroundJob.Schedule(
+                            () => mfaReminderJob.ExecuteAsync(identityEvent, cancellationToken),
+                            TimeSpan.FromHours(24));
+
+                        LogMessageProcessed(logger, messageId, eventType, null);
+                        processedCount++;
+                        break;
+
                     case "TestEvent":
                     case "OldEvent":
                     case "RecentEvent":