ghostty return unless command exists

tools/miaou-create

@@ -74,6 +74,8 @@ function mount_miaou_bash {
 }
 
 function infocmp_xterm_ghostty {
+  ! command -v ghostty >/dev/null && return
+
   local target="$1"
   local optional_project=${2:-}
   [[ -n $optional_project ]] && optional_project="--project $optional_project"