Logical deletion of messages

[Lxx-c]

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1. Is this request related to a challenge you're experiencing? Tell me about your story.

I want to add a logical deletion field to the conversation messages. I checked model.py and there is no such field. I would like to know if I add this field, will it be overwritten when I merge the code and perform a flask db upgrade next time? Or do you have plans to add this feature? Because sometimes some questions involve sensitive information. If it is called by a third-party user through the API SERVER, and the third-party user performs a logical deletion of the session record locally while we perform a physical deletion here, it will be difficult to verify when troubleshooting.  

2. Additional context or comments

No response

3. Can you help us with this feature?

• [x] I am interested in contributing to this feature.