Class LaravelUi5\Core\Exceptions\UnregisteredDashboardChildException

Raised by {@see \LaravelUi5\Core\Ui5\Dashboard\DefaultDashboardTransformer} when a dashboard group declares a child namespace ({@see \LaravelUi5\Core\Ui5\Contracts\Ui5DashboardGroupInterface::getChildNamespaces()}) that the registry can't resolve — the child artifact was never registered on its module via getCards() / getTiles().

This turns the old "register in two places" footgun into a checked invariant: a group can only compose artifacts that actually exist in the registry, and the failure surfaces loudly at composition instead of silently 404-ing the integration-card manifest fetch.