Edges connecting main flow nodes to handler section nodes (ON_EXCEPTION, ON_COMPLETION) now span different ELK root graphs. ELK throws UnsupportedGraphException when an edge connects nodes in different layout hierarchies. Skip these cross-root edges — the frontend doesn't render them anyway (handler sections are separated visually). Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>