feat(ghostty-tmux): create new session with destroy-unattached when ghostty running

Previously, when ghostty was already running,
the script would launch a new ghostty instance without proper tmux session management.
Now it creates a new tmux session with destroy-unattached option to properly clean up when the window closes.

Author: sabertazimi

dot_local/bin/executable_ghostty-tmux.sh

@@ -1,7 +1,7 @@
 #!/usr/bin/env bash
 
 if pgrep -x "ghostty" >/dev/null; then
-  ghostty &
+  ghostty -e sh -c "tmux new-session \; set-option destroy-unattached on" &
 else
   ghostty -e sh -c "tmux attach || tmux" &
 fi