Item 59: A `Due` an advisor cannot select within

The counterfactual-legitimacy round's second clause needs a scorekeeping practice that produces a Due whose extension an advisor cannot select within, and does not derive one. Without it, reason-mediated non-capture is a condition on an object nobody has exhibited: an advisor that can choose which of several equally-due responses the principal faces has shaped the outcome while every certificate and account stays internally valid.

Deliverable shape: a practice with the non-selection property and its witness, or an argument that no practice with the round's other properties has it. Acceptance check: the round's projection fixture runs against the practice, and a selecting advisor is distinguished from a non-selecting one by the coupled-run condition rather than by inspection. Context: projects/normativity/legitimacy/rounds/2026-08-17-counterfactual-legitimacy/THEOREM_MAP.md §6. Consumed by: any round composing actual-run answerability with counterfactual non-capture, which is the composition the legitimacy line's status block names as open.