use std::future::Future;use std::pin::Pin;use codex_protocol::models::ResponseInputItem;/// Future returned when an extension asks the host to inject model-visible input.pub type ResponseItemInjectionFuture<'a> =    Pin<Box<dyn Future<Output = Result<(), Vec<ResponseInputItem>>> + Send + 'a>>;/// Host-provided helper for extensions that need to steer the active model turn.////// Implementations should inject the supplied response items into the active turn/// when one can accept same-turn model input. If injection is unavailable, they/// return the unchanged items to the caller.pub trait ResponseItemInjector: Send + Sync {    fn inject_response_items<'a>(        &'a self,        items: Vec<ResponseInputItem>,    ) -> ResponseItemInjectionFuture<'a>;}/// Injector used when a host does not expose same-turn model steering.#[derive(Debug, Default, Clone, Copy)]pub struct NoopResponseItemInjector;impl ResponseItemInjector for NoopResponseItemInjector {    fn inject_response_items<'a>(        &'a self,        items: Vec<ResponseInputItem>,    ) -> ResponseItemInjectionFuture<'a> {        Box::pin(std::future::ready(Err(items)))    }}