Function execute_graph_operation 

pub async fn execute_graph_operation(
    query: Query,
) -> Result<OperationOutcome, DynError>

Executes a graph query expected to return exactly one row containing a boolean column named “flag”. Interprets the boolean as follows:

• true => Returns OperationOutcome::Updated
• false => Returns OperationOutcome::CreatedOrDeleted

If no rows are returned, this function returns OperationOutcome::MissingDependency, typically indicating a missing dependency or an unmatched query condition.