A conversation with direction
The student does not enter a general-purpose chat. The screen presents one system question and one place to answer it. Every intervention comes from the previous answer and the current step of the task.
The student does not start another topic
The interaction stays bounded to the task and the concept needed to progress. When an answer is unrelated, it can be detected before spending an external model call.
Help without becoming a solver
The student can request help with the current step. Mayéutica can move backwards, change the question or use supporting material, but it does not open a free chat that can solve anything outside the activity.