JSON tree export for external visualization

[ToySin]

Summary

Export tree structure and node status as JSON, enabling integration with external visualization tools (web UI, Graphviz, etc).

Details

• ExportJSON(tree *Tree) ([]byte, error) — serialize tree structure with node type, name, status, children
• Output should include all information needed to render the tree externally
• Example output:

  {
    "type": "Fallback",
    "name": "dispatch",
    "status": "Success",
    "children": [
      {
        "type": "Sequence",
        "name": "try-assign",
        "status": "Failure",
        "children": [...]
      }
    ]
  }

Scope

Low priority — groundwork for future rich visualization (web dashboard, real-time monitoring, etc).