Enhance Mention Widget Visibility for New Comments

The Mention widget should automatically prioritize active conversations by moving any existing thread with a newly added comment to the top of the widget. This would improve visibility and help users quickly identify and respond to recent activity.

Currently, users must scroll through the widget to locate new comments if the original thread was created some time ago, since thread placement is based on the thread's start date rather than the most recent comment. Reordering threads based on the latest activity would create a more intuitive and efficient user experience.