Method remapLayoutKeysAfterReorder

app/src/DataModel/ProjectModel.cpp:3971–3996

* @brief Rewrites every layout:N widgetSettings entry to use the new groupId. */

 * @brief Rewrites every layout:N widgetSettings entry to use the new groupId.
 */
void DataModel::ProjectModel::remapLayoutKeysAfterReorder(const std::vector<int>& oldToNewGid)
{
  if (m_widgetSettings.isEmpty())
    return;

  const QString prefix = QStringLiteral("layout:");
  QMap<int, QJsonObject> snapshot;

  for (const auto& key : m_widgetSettings.keys()) {
    if (!key.startsWith(prefix))
      continue;

    bool ok      = false;
    const int id = key.mid(prefix.length()).toInt(&ok);
    if (!ok || id < 0 || static_cast<size_t>(id) >= oldToNewGid.size())
      continue;

    snapshot.insert(id, m_widgetSettings.value(key).toObject());
    m_widgetSettings.remove(key);
  }

  for (auto it = snapshot.constBegin(); it != snapshot.constEnd(); ++it) {
    const int newId = oldToNewGid[static_cast<size_t>(it.key())];
    m_widgetSettings.insert(Keys::layoutKey(newId), it.value());
  }
}

/**
 * @brief Renames per-group auto workspaces (PerGroupStart + groupId) so they