The audit said adopt the shared BackButton. It is not shared: zero importers
since the initial commit, no barrel entry, and a label-plus-underline shape
that fits none of the icon-only back controls here. Adopting it would have
redesigned the Jobs header under cover of a navigation fix.
So: a Link, matching what ScriptJobDetail and DownloadJobDetail already do,
and the dead component goes. useNavigate had no other caller in
PipelineJobDetail and goes with it.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>