feat(service): outbox relay + thread read endpoint + replay (P1.5, P1 complete)

OutboxRelay: FOR UPDATE SKIP LOCKED claim, in-process bus publish, PENDING->
PUBLISHED with 30s backoff + idempotent-consumer ledger. GET /v1/threads/:id/
messages (policy-scoped). Replay + read specs green; vitest fileParallelism off
(shared DB). End-to-end HTTP smoke verified: idempotent ingest, read-back, 400
on missing key. 19 tests pass.

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

packages/iios-service/src/outbox/outbox.module.ts

@@ -0,0 +1,9 @@
+import { Module } from '@nestjs/common';
+import { OutboxBus } from './outbox.bus';
+import { OutboxRelay } from './outbox.relay';
+
+@Module({
+  providers: [OutboxBus, OutboxRelay],
+  exports: [OutboxBus, OutboxRelay],
+})
+export class OutboxModule {}