Mark lifecycle methods as nodoc

Editor assessment

Mark lifecycle methods as nodoc is compressed jargon: the reader must know that nodoc is the docs tooling's suppression marker to understand that these methods are deliberately hidden from the API reference, and no body explains why hiding them is right. The common scope and docs type are plausible and hygiene is clean, but the message is understandable mainly to insiders. Defining nodoc and explaining why suppression is right for lifecycle methods would have opened the message to outside readers.