Refactor settings menu and exit handling in build.func

Simplifies the menu item logic for settings and app defaults, updates the whiptail menu to use custom button labels, and replaces direct exit calls with the exit_script function for consistent script termination.

misc/build.func

@@ -1551,26 +1551,22 @@ install_script() {
       "4" "My Defaults"
     )
 
-    local next=5
     if [ -f "$(get_app_defaults_path)" ]; then
-      menu_items+=("$next" "App Defaults for ${APP}")
+      menu_items+=("5" "App Defaults for ${APP}")
-      next=$((next + 1))
+      menu_items+=("6" "Settings")
+    else
+      menu_items+=("5" "Settings")
     fi
 
-    menu_items+=(
-      "$next" "Settings"
-      "$((next + 1))" "Exit"
-    )
-
     TMP_CHOICE=$(whiptail --backtitle "[dev] Proxmox VE Helper Scripts" \
       --title "SETTINGS" \
+      --ok-button "OK" --cancel-button "Exit Script" \
       --menu "Choose an option:" 20 60 9 \
       "${menu_items[@]}" \
       --default-item "1" 3>&1 1>&2 2>&3) || true
 
     if [ -z "$TMP_CHOICE" ]; then
-      echo -e "\n${CROSS}${RD}Menu canceled. Exiting script.${CL}\n"
+      exit_script
-      exit 0
     fi
     CHOICE="$TMP_CHOICE"
   fi
@@ -1629,10 +1625,6 @@ install_script() {
     settings_menu
     exit 0
     ;;
-  7)
-    echo -e "\n${CROSS}${RD}Script terminated.${CL}\n"
-    exit 0
-    ;;
   *)
     echo -e "${CROSS}${RD}Invalid option, please try again.${CL}"
     ;;