Supports create, read, update, delete, and list operations.

Args:
    operation: Operation to perform (create, read, update, delete, list)
    node_type: Type of node (SKILL, KNOWLEDGE, SCRIPT, ENV)
    node_id: Node ID (for read, update, delete)
    data: Node data (for create, update) - can be dict or JSON string
    filters: Filter criteria (for list) - can be dict or JSON string

Returns:
    Operation result

SCRIPT Node Best Practices:
    - Do NOT include `if __name__ == '__main__':` blocks - they are
      automatically stripped during execution to prevent unintended side effects
    - Export functions/classes that should be callable from user code
    - Keep example/test code in separate functions, not in __main__ blocks
    - Use PEP 723 metadata for dependencies
    - To use environment variables, create an ENV node and connect it to the
      SCRIPT using a CONTAINS relationship: SCRIPT -[:CONTAINS]-> ENV
      The ENV variables will be automatically loaded during execution

Examples:
    Create a SKILL node:
    ```
    nodes(
        operation="create",
        node_type="SKILL",
        data={
            "name": "data-pipeline",
            "description": "ETL pipeline for data processing",
            "body": "# Data Pipeline\n\nThis skill..."
        }
    )
    ```

    Create a SCRIPT node (note: no __main__ block):
    ```
    nodes(
        operation="create",
        node_type="SCRIPT",
        data={
            "name": "fetch_data",
            "description": "Fetch data from API",
            "function_signature": "fetch_data(url: str) -> dict",
            "body": '''# /// script

    List SCRIPT nodes:
    ```
    nodes(
        operation="list",
        node_type="SCRIPT",
        filters={"name": "fetch"}
    )
    ```