The agent now sends shallow copies (without children) in the flat nodes list. Build nodeById map by walking graph.getRoot() tree which preserves children, falling back to flat list via putIfAbsent for compatibility. Also adds EIP_FILTER, EIP_IDEMPOTENT_CONSUMER, EIP_RECIPIENT_LIST as new compound container types per updated DIAGRAMS.md. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>