Consistency checks over the MetaTrace instances.

These need no trace values: everything here is derived from allNamespaces and the namespace-indexed methods. That makes them cheap enough to run over every traced type. What they check is that every namespace in allNamespaces is well formed: it is non-empty and unique, and it has a severity (a missing one silently makes the message unconfigurable), a privacy, a detail level and documentation, each of which has to be answerable from the namespace alone, since the methods are queried with no trace value. And that trace-dispatcher accepts the resulting tree, so that every namespace is addressable.

What they do not check is the other direction: namespaceFor is never called, so a constructor whose namespace is missing from allNamespaces, or a typo that appears in both places, still passes. Catching that needs trace values, and these types have neither Arbitrary nor Enum instances.