validate_site reached complexity 43 doing three things at once. The
per-page checks and the link resolution are now separate functions and
the caller keeps only the cross-page duplicate check, which cannot run
until every page has been seen.
The first attempt left the link pass calling a closure that had moved,
and running it against the real site did not catch that: no page there
has a broken link, so the error path never ran. The unit test covering
a deliberately broken fragment did.
Abdessamad Derraz
0a941acc43