`howl`: optionally specify run info and events topics

these are currently defaulted to `topic_prefix` but we might want a way of manuall specifying them (these args would be mutually exclusive to topic_prefix)

Start by locating the `howl` entry point and its existing `topic_prefix` handling. Trace how the run-info and events topics are currently derived, then inspect any related argument or configuration tests. Done means callers can specify both topics independently, while `topic_prefix` is mutually exclusive with those explicit options and the valid and conflicting combinations are covered.

Written by the indexing model from the issue text.