Configuration must initially come from mock JSON and later from backend API without changing consumers. `ConfigService` is the only configuration entrypoint; consumers depend on typed selectors only; provider implementation is swappable (`MockBootstrapProvider` / `ApiBootstrapProvider`); the frontend calls `GET /bootstrap` when the API provider is enabled and never passes a tenant id.
This decision remains in effect. The full, verified contract — endpoint, caching, field-by-field DTO reference, and the generalized mock↔API provider-swap pattern this ADR introduced (now used by every admin domain, not just bootstrap) — lives in `docs/backend/BACKEND-INTEGRATION.md`. Read that document for current, code-verified detail; this file is kept only so ADR-numbered references in `docs/architecture/foundation/README.md` continue to resolve.