feat: Add phone number validation to order confirmation

- Implemented phone number normalization and validation in custom_js.js.
- Added alert class to phone input on validation failure.
- Disabled confirm button until a valid phone number is entered.
- Updated custom.scss to style alert state for phone input.
- Modified footer.tpl to include a new custom JavaScript file.
- Updated head.tpl to reflect the new version of custom.css.
- Minor formatting adjustments in existing CSS and JS files.

themes/charme/assets/css/custom.scss

@@ -426,4 +426,8 @@ body#product {
       display: none !important;
     }
   }
+}
+
+.form-control.alert {
+  border: 1px solid #cc0000 !important;
 }