Description:
In the MediaWiki namespace (e.g. MediaWiki:Edittools), the Chinese language variant conversion tags such as-{zh-cn:全角; zh-tw:全形;}- are not parsed or rendered. Instead, they appear as raw wikitext. This affects the multilingual interface usability, especially on user-facing system messages.

This issue seems specific to the MediaWiki namespace, as the same tags work properly in normal content namespaces.

However, in the https://zh.wikipedia.beta.wmflabs.org site running MediaWiki 1.45.0-alpha (9819cba), the same conversion tags are displayed correctly even in the MediaWiki namespace.

This suggests the issue might have already been fixed in newer versions of MediaWiki but remains present on production wikis like zh.wikipedia.org.

Steps to reproduce (on production wiki such as zh.wikipedia.org):

1. Visit any article (e.g., https://zh.wikipedia.org/wiki/狗), click “Edit”.
2. Observe the content under the editing textbox (Edittools area):
3. The conversion tag is not parsed — it appears as raw wikitext.
4. However, viewing the MediaWiki:Edittools page directly shows correct rendering.

Expected behavior:
Conversion tags should be parsed and rendered according to the user's language preference, even in the MediaWiki namespace.

Environment:

Affected: zh.wikipedia.org (as of June 2025)

Working: zh.wikipedia.beta.wmflabs.org (MediaWiki 1.45.0-alpha)