Username Highlight Not Working in Notification When User Language is Set to Russian

Description:

When a user’s language in Rocket.Chat is set to Russian, mentions (e.g., @username) do not properly highlight the username in the chat, as seen with Rocket.Cat bot notification. Specifically, the issue was observed when @anirban was mentioned, but the username was not highlighted in the message. This issue does not occur with other languages like English, where mentions properly highlight the username.

Steps to reproduce:

1. Open Rocket.Chat Desktop Client
2. Go to Preferences
3. Select Russian as Language from dropdown --> Save Changes
4. Open any channel -> navigate to Members -> Click on Add
5. Choose existing members from the list and click on Add Users
6. Notice the rocket.cat message that comes up

Expected behavior:

The mentioned username should be highlighted regardless of the user’s language setting.

Actual behavior:

In the Russian language setting, the username is not highlighted , but works fine in English.

Server Setup Information:

• Version of Rocket.Chat Server: 7.1.0
• Operating System: Linux
• DB Replicaset Oplog: Yes
• NodeJS Version: 20.18.0
• MongoDB Version: 7.0.5

Client Setup Information

• Desktop App or Browser Version: N/A
• Operating System: Windows

Additional context

Relevant logs:

No source files or tests are identified in the issue. Reproduce the notification mention with Russian selected, then compare it with English to trace the mention-rendering path; done means the username is highlighted consistently across both language settings.