Function load_memory_appendix_async 

pub async fn load_memory_appendix_async(
    workspace_root: &Path,
    agent_name: &str,
    scope: Option<SubagentMemoryScope>,
) -> Result<Option<String>>

Async variant of load_memory_appendix for child-agent prompt assembly.

Directory creation, existence checks, and file reads use Tokio’s filesystem boundary so launching a child agent does not block an executor worker.