Declare My Age

A student answering "are you under 18?", first time or correcting.

ONE endpoint for both, because they are the same act with different timing and the rule that governs them is identical: a student's answer may tighten the gate and may never loosen it (parental_consent_service.set_minor). Saying you are a minor takes effect at once. Saying you are NOT, when something already says you are, is recorded and raised to the coordinator rather than acted on, or "declare yourself a minor, then declare yourself an adult" would be a way out for anybody.

That second case is not a hypothetical. One button on an activation screen decides whether a student can use their course, people tap the wrong one, and the activation link is spent afterwards — so without this the mis-click is a dead end with no route to anyone.