feat(renderer): add modifyOtherKeys support (#1579)

Modified keys (shift+enter, ctrl+i, etc.) don't work in tmux because
tmux doesn't support the Kitty keyboard protocol. tmux requires
applications to request extended-keys using modifyOtherKeys (CSI > 4 ; 2 m).

The workaround is setting 'extended-keys always' in tmux config (tmux 3.2+),
but users may not know this is the issue, and forcing extended-keys for all
applications may not be desired. This fix sends modifyOtherKeys requests
alongside Kitty protocol sequences, enabling proper key handling in tmux
automatically.