feat(p7): AI tables + enums + migration + events + InferencePort contract

Task 7.1: 7 AI-proposal-layer tables (IiosAiJob, IiosAiModelRun, IiosAiArtifact,
IiosAiClaim, IiosAiEvidenceLink, IiosAiToolCall, IiosEmbeddingRef) + enums;
migration ai-init. Adds ai.job.created / ai.artifact.proposed / ai.artifact.accepted
events and a standalone InferencePort contract (not part of sealed IiosPlatformPorts).
resetDb truncates the new tables.

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

packages/iios-contracts/src/events.ts

@@ -43,6 +43,9 @@ export const IIOS_EVENTS = {
   callbackRequested: 'com.insignia.iios.support.callback.requested.v1',
   routeDecisionPreviewed: 'com.insignia.iios.route.decision.previewed.v1',
   routeApproved: 'com.insignia.iios.route.approved.v1',
+  aiJobCreated: 'com.insignia.iios.ai.job.created.v1',
+  aiArtifactProposed: 'com.insignia.iios.ai.artifact.proposed.v1',
+  aiArtifactAccepted: 'com.insignia.iios.ai.artifact.accepted.v1',
   notificationQueued: 'com.insignia.iios.notification.queued.v1',
   deliveryAttempted: 'com.insignia.iios.delivery.attempted.v1',
 } as const;