The Ctrl+G handler was toggling the alt-screen by hand
(`\x1b[?1049l` ... `\x1b[?1049h`) without releasing stdin or kitty
keyboard mode, so the launched editor would lose keystrokes (Ink kept
swallowing them) and editors that don't speak CSI-u (e.g. nano) would
print "Unknown sequence" for every Ctrl-key.
Switch to `withInkSuspended` from @hermes/ink, the same helper
`/setup` already uses. It pauses Ink, removes stdin listeners, drops
raw mode, disables kitty/modifyOtherKeys + mouse + focus reporting,
runs the editor, then restores everything with a full repaint.