[dinfinity]

The solution is almost trivial and well known:

Document. Whenever a member of the team leaves, you should always make them document what is in their head and not already documented (or even better, make documenting a required part of normal development).

The thing to understand is that every (new) AI chat session is effectively a member entering and leaving your team. So to make that work well you need great onboarding (provide documentation) and great offboarding (require documentation).