- Add ProjectorIdempotencyGuard for idempotent event processing protection
- Add CleanupProjectorProcessedEventsCommand for maintenance
- Add projector_processed_events schema SQL
- Update ecs.php to modern ECSConfig API
- Update phpstan.neon excludePaths key
- Add integration test suite to phpunit.xml.dist

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>