Function cancel_cli_login 

pub fn cancel_cli_login(state: &Arc<AppState>) -> Result<Value, String>

Kill the in-progress CLI login process. Covers both transports: the pipe path uses a oneshot to drop the Tokio Child (kill_on_drop terminates the subprocess); the PTY path uses platform-specific kill-by-PID because the portable_pty::Child lives inside a spawn_blocking task that doesn’t react to outer-task abort.