Class Logger

Apply options; unset fields keep their current value.

Product output: the run summary, printed verbatim.

Distinct from info because the summary is the thing the run exists to produce, not a note about producing it. Routing it through the log formatter prefixed every line with a timestamp and a level, which pushed the box borders out of alignment and made the headline artefact look broken.

Redirect output, returning the previous sink so the caller can restore it. Passing null restores the real streams.