Cut over public engine construction to ConfigKit sources

internal/configuration/targets.go

@@ -177,3 +177,14 @@ func (state *loaded) GetBackend(id string) (domain.Backend, error) {
 	}
 	return state.registry.GetBackend(id)
 }
+
+// CapacityPolicies returns the selected backend admission policies.
+func (state *loaded) CapacityPolicies() map[string]domain.BackendCapacityPolicy {
+	if state == nil {
+		return nil
+	}
+	return state.registry.CapacityPolicies()
+}
+
+// ExactIDs indicates that ConfigKit definition keys are literal identities.
+func (state *loaded) ExactIDs() bool { return true }