When writing a comment, users should be able to use @ to mention or assign another user and # to reference or link another comment.
tested in issue view page and not model page, in the model page @ is working.
Desired behavior:
- Typing @ should open a list of available users and allow selecting a user.
- Typing # should allow users to search for and link an existing comment or issue.
- Mentions and linked comments should be clickable for quick navigation.