Step Validation Bug

Problem/Motivation

The range-slider-element implementation conflicts with step validation for range inputs. Instead of validating steps relative to the min attribute (the step base), it validates relative to 0.
This causes range sliders to snap to incorrect values when min is not a multiple of step, violating the HTML5 specification and providing unexpected user experience.

Steps to reproduce

Create a slider using these attributes:

   $form['slider'] = [
     '#type' => 'range_slider',
     '#min' => 5,
     '#max' => 30,
     '#step' => 2,
     '#default_value' => 6,
   ];

Proposed resolution

See if the issue can be fixed upstream first https://github.com/andreruffert/range-slider-element/pull/210

Remaining tasks

User interface changes

API changes

Data model changes