Feature request: Lock individual chats with Face ID/PIN

Many users occasionally hand their phone to a family member, child, friend, or colleague so they can ask ChatGPT a quick question. While the app itself can be protected by the phone’s lock screen, there is currently no way to protect specific conversations containing sensitive personal, medical, financial, or work-related information. Please add the ability to: * Lock individual chats with Face ID, Touch ID, or a PIN. * Move sensitive chats into a protected folder. * Optionally hide locked chats from the main conversation list until authenticated. This would significantly improve privacy without making the app harder to use.