Directionality of text is not respected in MathML output

Issue Summary

dir attribute can be used to change the text direction even on individual MathML elements. MathJax does not respect this in rendering.

MathJax 4 output:

Expected output (Firefox's native):

OS: Windows 11
Browser: Mozilla Firefox 153.0

Steps to Reproduce:

Render the code:

<math xmlns="http://www.w3.org/1998/Math/MathML" dir="rtl">
  <mi>n</mi>
  <mo>=</mo>
  <mfrac>
    <mrow>
      <mn>1</mn>
      <mo>+</mo>
      <msqrt>
        <mn>5</mn>
      </msqrt>
    </mrow>
    <mn>2</mn>
  </mfrac>
</math>

Attribute dir="rtl" should make so that the text direction changes.

Technical details:

• MathJax Version: 4
• OS: Windows 11
• Browser: Mozilla Firefox 153.0

I am using the default following MathJax configuration and and loading MathJax via

<script src="https://cdn.jsdelivr.net/npm/mathjax@4/tex-mml-chtml.js" defer></script>

Start by loading the provided MathML example through tex-mml-chtml.js and compare the MathJax output with Firefox's native rendering. Trace how the MathML dir attribute is handled during output generation, then verify that dir="rtl" on an individual MathML element changes the rendered direction and add regression coverage for the example.