Spelling is not working, the list of languages is weird

Hi! I've found that the spelling doesn't work at all - the wrong words are not underlined. Is this feature present in the `ds example` of the documentserver docker image?

Trying to select the language of the document I am facing with the weird list of languages:

<img width="625" height="411" alt="Image" src="https://github.com/user-attachments/assets/fe22013a-00dc-4990-8afa-f09cb650968a" />