Export EventDescriptor, defineEvent, IEventBus, EventHandler,
CORE_EVENTS_SYMBOLS, InMemoryEventBus, InMemoryEventBusOptions, and
PayloadJobsEventBus from src/index.ts. All typecheck, test (11 tests),
and lint checks pass. turbo boundaries: 454 files, no issues.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
