Struct LauncherIpcHandle 

pub struct LauncherIpcHandle {
    writer: Arc<Mutex<WriteHalf<NamedPipeClient>>>,
    reader_task: JoinHandle<()>,
}

Handle the host holds for its lifetime so the launcher’s IPC pipe stays open. Dropping it closes the connection (launcher logs as a disconnect).

Cross-platform shape: the Windows variant carries the actual pipe writer + reader-task handles; the non-Windows variant is a unit-struct stub so connect_to_launcher keeps a uniform Option<LauncherIpcHandle> return type. Phase 7’s cross- platform IPC (Unix domain sockets) will fill the non-Windows shape later. (reagent / codex P1 PR #573 round-1.)

Fields

writer: Arc<Mutex<WriteHalf<NamedPipeClient>>>

Held purely as a keepalive; B.3+ will replace with a real command-sender that uses this writer.

reader_task: JoinHandle<()>

Read-half task handle. Currently just consumes bytes off the wire and logs them. B.4+ replaces with an event dispatcher.