feat(testkit): deterministic fake platform ports + fixtures + replay oracle

Fakes for all 7 IiosPlatformPorts (deny/timeout/ambiguous controls), portal +
unknown-email fixtures, replayTwice idempotency oracle. Adds ingest request
contract. Vitest alias resolves workspace packages to source.

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

packages/iios-testkit/src/index.ts

@@ -0,0 +1,4 @@
+export * from './fakes';
+export * from './replay';
+export { portalMessageBasic } from './fixtures/portal-message-basic';
+export { emailFromUnknown } from './fixtures/email-from-unknown';