refactor(forum): pass the request as an action argument
Controllers are container singletons, so a Request injected into the constructor outlives the request it belongs to. Every forum controller now takes it as the first action argument; private helpers receive it as a parameter.
ForumUtils::topicLink() no longer resolves the request from the container: it needs the host only, which the caller now passes as a string.
ForumUtils::topicLink() no longer resolves the request from the container: it needs the host only, which the caller now passes as a string.