Function runtime_group_unique_id

app/src/DataModel/Frame.h:1001–1004

* @brief Deterministic uniqueId for a runtime-synthesised group. */

 * @brief Deterministic uniqueId for a runtime-synthesised group.
 */
[[nodiscard]] inline constexpr int runtime_group_unique_id(int groupId) noexcept
{
  return kRuntimeGroupUidBase + groupId;
}

/**
 * @brief Single source of truth for the (source, group, dataset) -> uniqueId mapping.