Individual Conversation Locking: The ability to lock specific chats (private or group) using a PIN, Fingerprint, or Face ID, separate from the main app lock.
​Hidden Mode: Once locked, the chat should be hidden from the main chat list. It would only reappear when a specific code is entered into the search bar or through a "Hidden Folders" section.
​Privacy Notifications: Notifications from these locked chats should not display the sender's name or the message preview (e.g., showing only "1 New Message").