List the compute family classes a commitment can cover in this scope

Returns the compute family CLASSES (General-purpose / Compute-optimized / …) a commitment can cover in the active scope, as { data: [CommitmentEligibleService] } — the options of the Savings-Plan classScope and the Reserved-Instance family selector in the commitment creation form. Coverage is compute-only. A class is listed only when it is BOTH (a) eligible under the admin discount matrix for at least one commitment type and (b) backed by a compute SKU of that class with a positive effective HOUR rate in the subscription's default region (ist-1 when the subscription has none), so the picker never offers a class a purchase would then reject. Keyed on the billing grain (scope_id == subscription_id). The list is not paginated and carries no meta. Validation: scopeId must resolve to a scope the caller can reach (unknown → 404 NOT_FOUND); no other inputs. RBAC: READ on billing plus the billing:read token scope, held at SUBSCRIPTION level — a grant on the path project alone is refused 403 (details.reason SUBSCRIPTION_ROLE_REQUIRED). Async & state: Synchronous read; no state change. Errors: 401 unauthenticated; 403 caller lacks subscription-level billing READ or the token scope; 404 unknown scopeId; 500 internal failure. Idempotency/Concurrency: Safe, cacheable; no idempotency key required.