feat(risk): add typed RiskEvaluatedEvent payload and unit tests for risk scoring audit trail (#414)

src/events/risk-evaluated.event.spec.ts

@@ -0,0 +1,34 @@
+import { describe, it, expect } from 'vitest';
+import { RiskEvaluatedEvent } from './risk-evaluated.event';
+import { DomainEventName } from './event-names';
+
+describe('RiskEvaluatedEvent (#414)', () => {
+  it('constructs an immutable risk evaluation event with score, band, and factors', () => {
+    const evt = new RiskEvaluatedEvent(
+      'org_123',
+      {
+        transactionId: 'tx_999',
+        score: 82,
+        band: 'HIGH',
+        factors: [
+          {
+            factor: 'amount',
+            weight: 30,
+            contribution: 25,
+            detail: 'Exceeds standard agent transfer limit',
+          },
+        ],
+        canAutoExecute: false,
+      },
+      'agent_42',
+    );
+
+    expect(RiskEvaluatedEvent.eventName).toBe(DomainEventName.RiskEvaluated);
+    expect(evt.organizationId).toBe('org_123');
+    expect(evt.payload.score).toBe(82);
+    expect(evt.payload.band).toBe('HIGH');
+    expect(evt.payload.canAutoExecute).toBe(false);
+    expect(evt.actorId).toBe('agent_42');
+    expect(evt.occurredAt).toBeInstanceOf(Date);
+  });
+});

src/events/risk-evaluated.event.ts

@@ -0,0 +1,26 @@
+import { RiskBand } from '@prisma/client';
+import { DomainEventName } from './event-names';
+import { RiskFactorScore } from '../modules/risk/risk.types';
+
+export interface RiskEvaluatedEventPayload {
+  transactionId?: string;
+  score: number;
+  band: RiskBand;
+  factors: RiskFactorScore[];
+  canAutoExecute: boolean;
+}
+
+/**
+ * Strongly typed domain event emitted whenever an agent transaction undergoes
+ * risk scoring so downstream audit listeners persist immutable risk metadata.
+ */
+export class RiskEvaluatedEvent {
+  static readonly eventName = DomainEventName.RiskEvaluated;
+
+  constructor(
+    public readonly organizationId: string,
+    public readonly payload: RiskEvaluatedEventPayload,
+    public readonly actorId?: string,
+    public readonly occurredAt: Date = new Date(),
+  ) {}
+}