Code-quality review nits: IEventBus.subscribe docstring said "debug
tag" but InMemoryEventBus actually ignores the param entirely. Also
add a comment to InMemoryEventBus.publish noting that under failFast
only the first rejection rethrows; other failures are intentionally
dropped.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>