Non-functional requirements registry

ID	Quality attribute / constraint	Measurable target	Status
NFR-0001	Payment credential isolation	No secret in browser bundles, logs, Git, or committed configuration	Proposed; implementation candidate
NFR-0002	Accessibility	Keyboard-operable journey, visible focus, semantic status, WCAG AA contrast target	Proposed; implementation candidate
NFR-0003	Catalog and amount integrity	Unknown products rejected; server totals reconstructed from canonical data	Proposed; implementation candidate