Setup wizard panels

The setup wizard (/{user}/GettingStarted, the AI engine's OnboardingWizardArea) is assembled from panels packages contribute as data: a UiContribution node with context: Onboarding. The child Voice is this package's panel — Your voice assistant, in the home chapter. It is a hand-off: naming the assistant and recording the family's wake phrase happen in the Memex phone app (You → Voice assistant), because both talk to the voice gateway on the home network, which the portal cannot reach. The panel opens the Voice guide, which describes the steps. Shown to someone who holds the package.