feat(service): P3.2 InboxProjector + message.read event + scheduled relay

Event-driven projector creates/collapses NEEDS_REPLY items from message.sent
(traceId propagated; inbox.item.created emitted) and resolves them to DONE on
message.read; idempotent via processed-event ledger. markRead now emits a
message.read outbox event (atomic). OutboxRelay runs on a 500ms timer in the
app (off in tests). Shared resetDb (TRUNCATE CASCADE) fixes cross-spec FK
isolation. 32 tests green.

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

packages/iios-service/src/threads/threads.spec.ts

@@ -1,5 +1,6 @@
 import { describe, it, expect, beforeAll, afterAll, beforeEach } from 'vitest';
 import { PrismaClient } from '@prisma/client';
+import { resetDb } from '../test-utils/reset-db';
 import { makeFakePorts, portalMessageBasic } from '@insignia/iios-testkit';
 import { IngestService } from '../interactions/ingest.service';
 import { ThreadsService } from './threads.service';
@@ -10,16 +11,7 @@ const prisma = new PrismaClient({ datasources: { db: { url } } });
 const asService = prisma as unknown as PrismaService;
 
 async function clean(): Promise<void> {
-  await prisma.iiosOutboxEvent.deleteMany();
-  await prisma.iiosProcessedEvent.deleteMany();
-  await prisma.iiosMessagePart.deleteMany();
-  await prisma.iiosInteraction.deleteMany();
-  await prisma.iiosThreadParticipant.deleteMany();
-  await prisma.iiosThread.deleteMany();
-  await prisma.iiosActorRef.deleteMany();
-  await prisma.iiosSourceHandle.deleteMany();
-  await prisma.iiosChannel.deleteMany();
-  await prisma.iiosScope.deleteMany();
+  await resetDb(prisma);
 }
 
 beforeAll(async () => { await prisma.$connect(); });