Right, you can only listen to container lifecycle events from an Extension, declared in META-INF, not from an ordinary bean. Check the package-level javadoc.
D'Oh. Always the same mistake. I've put the service file in /META-INF/services and not in /WEB-INF/classes/META-INF/service.
But thanks anyway.
Please use 1.0.0, I made quite a few fixes to the extensions support there.