fix(core-testing): align RecordingEventBus with real bus semantics

Handlers and the published record now receive the zod-PARSED payload
(defaults/coercions applied) instead of the raw input, and fan-out uses
Promise.allSettled with errors swallowed by default plus an opt-in
failFast — matching the InMemoryEventBus the events core-package
generator scaffolds. The previous sequential fail-fast divergence was
undocumented, so it is aligned rather than kept. Regression tests pin
parsed-payload delivery, non-short-circuiting fan-out, and failFast
rethrow. (S4; the generator bus templates already carry the fix.)

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

packages/core-testing/src/instrumentation/index.ts

@@ -2,7 +2,10 @@ export { RecordingTracer, type RecordedSpan } from "./recording-tracer";
 export { RecordingLogger, type RecordedCapture } from "./recording-logger";
 export { RecordingMetrics, type RecordedMetric } from "./recording-metrics";
 export { RecordingJobQueue } from "./recording-job-queue";
-export { RecordingEventBus } from "./recording-event-bus";
+export {
+  RecordingEventBus,
+  type RecordingEventBusOptions,
+} from "./recording-event-bus";
 export { RecordingRealtimeBroadcaster } from "./recording-realtime-broadcaster";
 export { RecordingAuditLog } from "./recording-audit-log";
 export {