Kitty: Command injection into the child shell via chained @kitty-echo + @kitty-ssh DCS escape sequences

Kitty is a cross-platform GPU based terminal. Prior to 0.48.2, the @kitty-echo and @kitty-ssh DCS handlers in kitty/window.py write unauthenticated data to the child shell's stdin, where handle_remote_echo accepts printable shell command characters and handle_remote_ssh calls get_ssh_data in kittens/ssh/utils.py, which emits a newline; chaining the handlers can execute attacker-controlled commands when a user displays untrusted terminal data. This issue is fixed in version 0.48.2.