International telephone element hidden by #states blocks form submission

AI-Generated: Yes (Claude Code was used to help draft this issue summary. I reviewed it.)

Problem/Motivation

A telephone element with "Enhance support for international phone numbers" is still validated on submit when #states hides it. With an invalid value, js/webform.element.telephone.js cancels the submit and puts "The phone number is not valid." under the hidden element. The user sees nothing and cannot submit the form. With clientside_validation there is a message at the top of the form, but it points to a field that is not visible.

Webform clears the value when #states hides an element, so this happens when "Clear value(s) when hidden" is off, or when a value arrives after the element was hidden (browser autofill, a password manager, a script). The same happens when the #states are on a container around the element.

Steps to reproduce

Drupal 11.4.12, Webform 6.3.1.

1. Create a webform with:
   

   show_phone:
     '#type': checkbox
     '#title': 'Show phone'
   phone:
     '#type': tel
     '#title': Phone
     '#international': true
     '#states_clear': false
     '#states':
       visible:
         ':input[name="show_phone"]':
           checked: true
   

2. Check "Show phone" and type +31 6 12.
3. Uncheck "Show phone".
4. Submit. Nothing happens and no error is visible.

Proposed resolution

Skip the submit validation for an element hidden by #states and clear its value, like #states_clear does. Elements on an inactive card or in a closed <details> are still validated.

Remaining tasks

Review the MR.

User interface changes

None.

API changes

None.

Data model changes

None.