Optional arm: DiPlugin. Omitted → decorated services are constructed directly and registered in the kernel's ServiceRegistry, which is the default and needs no container.

Supplying this arm changes how every decorated service in the application is constructed: DecoratorPlugin branches on the presence of a container, so with this arm each @Injectable class becomes a container provider that honors its scope. That is why it is gated rather than always-on — the default composition stays identical to a starter app without it.