Function add_create_rule 

pub fn add_create_rule(
    workspace_root: &Path,
    pattern: &str,
    schemas: &[String],
    default_cross_links: Option<&[CrossLinkTarget]>,
    before: Option<&str>,
) -> Result<Vec<WorkspaceEditWarning>, WorkspaceEditError>

memstead workspace allow-create <pattern> --schema <pin>[,…] [--cross-link …] [--before <pattern>] — append a [[mem_management.create]] rule. Default ordering is append (lowest priority); before flags lift it above the named pattern.