Grouping customisation for chat sessions

It would be beneficial to introduce a custom organisation/tagging for the sessions in the app.

A possible idea to implement this would be to add the option to add the session to a specific group in the contextual menu for the session, or add a tag to the session and introduce a grouping based on tags.

Start by reviewing the session UI and its contextual menu, which the issue identifies as possible entry points. Clarify whether the feature should use groups, tags, or both, then define how users assign sessions and view grouped sessions; done should include a clear interaction and behavior for session organization.

Do mô hình lập chỉ mục viết ra từ nội dung của issue.