Currently, chats are retained indefinitely unless manually deleted by the user (or started as ephemeral conversation). This can lead to clutter and unnecessary storage usage over time, both for users and for Proton.

I suggest adding a retention setting that allows users to specify how long unused chats should be kept before automatic deletion. Users could choose from predefined values (e.g., 1 month, 3 months, 6 months, 1 year, or "Never"). This feature will help users maintain a cleaner chat history, optimize storage resources, and enhance privacy.