An answer never changes Planning or the Rules: a conversation is only its messages, and only someone on the team decides what becomes a plan or a rule.
A conversation has no button to turn an answer into a plan or a rule: to keep what was agreed, add it yourself with Add plan in Planning or Add rule in Rules, where it goes through the usual AI check for duplicates and conflicts. A plan saved this way is a plan like any other, which the team can vote for, while a rule applies as soon as it is saved. Agents cannot do it for you: an agent's answer never changes the Planning, and agents never write rules.
When a plan or a rule settles what a conversation asked, say so in the conversation, for example with its six-character code, which a click on it copies. See How do I add a plan to Planning?.