fix: resolve CI failures from scope removal refactor

- Fix gofmt alignment in ops_realtime_models.go
- Remove SetAntigravityQuotaScopeLimit mock from api_contract_test.go
- Add UpdateSortOrders mock to mockGroupRepoForGateway

backend/internal/service/gateway_multiplatform_test.go

@@ -271,6 +271,10 @@ func (m *mockGroupRepoForGateway) GetAccountIDsByGroupIDs(ctx context.Context, g
 	return nil, nil
 }
 
+func (m *mockGroupRepoForGateway) UpdateSortOrders(ctx context.Context, updates []GroupSortOrderUpdate) error {
+	return nil
+}
+
 func ptr[T any](v T) *T {
 	return &v
 }