feat(iios): tenant-scoped /v1/dlq REST + chaos endpoint + smoke (P9 slice 5)

GET /v1/dlq lists the caller tenant's dead-letters; POST /v1/dlq/:id/replay
fences by assertOwns (KG-02) + audits each replay. Dev-only POST
/v1/dev/chaos/poison + ChaosConsumer (fails first delivery, succeeds on
replay) drive smoke-dlq.mjs: poison → QUARANTINED → cross-tenant denied →
owner replay → RESOLVED. Adds dev.chaos.v1 contract event.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

packages/iios-service/src/dev/dev.controller.ts

@@ -1,9 +1,13 @@
 import { randomUUID } from 'node:crypto';
-import { BadRequestException, Body, Controller, ForbiddenException, Param, Post } from '@nestjs/common';
+import { BadRequestException, Body, Controller, ForbiddenException, Headers, Param, Post } from '@nestjs/common';
 import jwt from 'jsonwebtoken';
+import { IIOS_EVENTS } from '@insignia/iios-contracts';
 import { hmacSign } from '@insignia/iios-adapter-sdk';
 import { InboundService } from '../adapters/inbound.service';
 import { AdapterRegistry } from '../adapters/adapter.registry';
+import { PrismaService } from '../prisma/prisma.service';
+import { ActorResolver, type MessagePrincipal } from '../identity/actor.resolver';
+import { SessionVerifier } from '../platform/session.verifier';
 
 /**
  * Dev-only helpers (gated by IIOS_DEV_TOKENS=1). Never enable in production.
@@ -13,6 +17,9 @@ export class DevController {
   constructor(
     private readonly inbound: InboundService,
     private readonly registry: AdapterRegistry,
+    private readonly prisma: PrismaService,
+    private readonly actors: ActorResolver,
+    private readonly session: SessionVerifier,
   ) {}
 
   @Post('token')
@@ -55,6 +62,46 @@ export class DevController {
     });
   }
 
+  /**
+   * Inject a poison chaos event into the outbox. The relay publishes it, the
+   * ChaosConsumer throws on first delivery → it is dead-lettered under the caller's
+   * scope, then `POST /v1/dlq/:id/replay` resolves it. Drives the DLQ smoke.
+   */
+  @Post('chaos/poison')
+  async poison(@Headers('authorization') auth?: string): Promise<{ eventId: string; scopeId: string }> {
+    this.assertDev();
+    const principal = this.principal(auth);
+    const scope = await this.actors.resolveScope(principal); // find-or-create so GET /v1/dlq matches
+    const id = `evt_chaos_${randomUUID()}`;
+    const cloudEvent = {
+      specversion: '1.0',
+      id,
+      type: IIOS_EVENTS.devChaos,
+      source: `iios/dev/${principal.appId}`,
+      subject: `chaos/${id}`,
+      time: new Date().toISOString(),
+      datacontenttype: 'application/json',
+      insignia: { scopeSnapshotId: scope.id, idempotencyKey: id, dataClass: 'internal' },
+      data: { poison: true },
+    };
+    await this.prisma.iiosOutboxEvent.create({
+      data: {
+        aggregateType: 'dev-chaos',
+        aggregateId: id,
+        eventType: IIOS_EVENTS.devChaos,
+        cloudEvent: cloudEvent as unknown as object,
+        partitionKey: `${principal.orgId}:${principal.appId}:chaos`,
+      },
+    });
+    return { eventId: id, scopeId: scope.id };
+  }
+
+  private principal(authorization?: string): MessagePrincipal {
+    const token = (authorization ?? '').replace(/^Bearer\s+/i, '');
+    if (!token) throw new BadRequestException('Authorization bearer token is required');
+    return this.session.verify(token);
+  }
+
   private assertDev(): void {
     if (process.env.IIOS_DEV_TOKENS !== '1') throw new ForbiddenException('dev endpoints disabled');
   }