- Replace `alternatives_considered` with structured `alternatives` array containing index(1-based), description, and chosen(boolean) fields in `_build_explain_dict()`
- Fix test fixture: add `chosen_option="GraphQL API"` to match an alternative so exactly_one_chosen assertion is correct
- Fix step pattern: replace fragile CSV-capture step with explicit field-checking step that validates all three keys (index, description, chosen)
- Update BDD scenarios and Robot Framework helpers for new field name
- Add CHANGELOG entry under [Unreleased]/Changed
ISSUES CLOSED: #9166
controller-ci-rerun
HAL9000