feat(p9): propagate trace id into emitted events + structured relay/gateway logs

Task O.2: ai/calendar/route/ingest emit sites now stamp traceparent + insignia.
correlationId from interaction.traceId ?? currentTraceId() ?? generated (mirroring
message.send; inbox/inbound already carried correlationId). toTraceparent is hex-safe
(UUID used as-is, other ids hashed). OutboxRelay logs a structured relay.publish per
event (eventType/aggregateId/correlationId); MessageGateway logs ws.deliver. Tests:
an event's correlationId equals the active request trace, with a generated fallback.

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

packages/iios-service/src/interactions/ingest.service.ts

@@ -7,6 +7,7 @@ import {
   IngestInteractionRequest,
   IngestInteractionResponse,
 } from '@insignia/iios-contracts';
+import { currentTraceId, newTraceId, toTraceparent } from '../observability/trace-context';
 import { PrismaService } from '../prisma/prisma.service';
 import { PLATFORM_PORTS } from '../platform/platform-ports';
 import { decideOrThrow } from '../platform/fail-closed';
@@ -188,8 +189,10 @@ export class IngestService {
           subject: `interaction/${created.id}`,
           time: new Date().toISOString(),
           datacontenttype: 'application/json',
+          traceparent: toTraceparent(created.traceId ?? currentTraceId() ?? newTraceId()),
           insignia: {
             scopeSnapshotId: scope.id,
+            correlationId: created.traceId ?? currentTraceId() ?? newTraceId(),
             policyDecisionId: decision.decisionRef,
             idempotencyKey,
             dataClass: 'internal',