CKEditor 5: Paste from Word fails to parse footnotes using modern HTML structures (li.footnote-definition)

Problem/Motivation

When pasting content from modern versions of Microsoft Word or LibreOffice into CKEditor 5, the footnote transformation logic fails. The current implementation in footnotesediting.js expects a flat structure where the footnote paragraph is a direct child of an element with an ID (e.g., [id*="ftn"] > p).

However, modern "Paste from Office" filters often wrap footnotes in a more structured format:

<ol class="footnotes">
  <li class="footnote-definition" id="ftn1">
    <a class="footnote-backlink" href="#ref-ftn1">^</a>
    <div class="footnote-content">
      <p>Footnote text here...</p>
    </div>
  </li>
</ol>

Because the <p> is nested inside a div, and the backlink <a> is a sibling rather than a child of the paragraph, the current selectors return 0 matches, leaving the raw Word HTML in the editor instead of converting it to Drupal <footnotes> tags.

Proposed resolution

Update transformClipboardContent in footnotesediting.js to use more resilient selectors:

• Descendant Selector: Change [id*="ftn"] > p to [id*="ftn"] p to catch nested paragraphs.
• Container Logic: Use .closest() or generalized ID selectors to find the footnote wrapper, allowing support for both <li> and <div> tags.
• Backlink Class: Include .footnote-backlink in the anchor search logic.
• Null Safety: Add checks to ensure anchorDiv exists before attempting DOM manipulation to prevent JS errors during paste.

Remaining tasks

• Review the proposed Javascript changes.
• Verify compatibility with legacy Word HTML formats.