The checker history records the URLs that failed, but a bare URL does not
say which channel or list it belongs to, so acting on it means matching
891 URLs against 97 files by hand.
It also does not say why a URL failed, and the reasons need different
answers. A 404 means the stream is gone. A 403 is what a channel served
only inside its own country looks like from outside it, and those are in
the lists on purpose. A connection that times out may just be a host
having a bad day.
This reports the channel and the list next to each URL, probes each one
several times so a single blip cannot condemn a channel, and separates
dead from blocked, unreachable and flaky. It reads both playlist formats
the lists use, so a DASH stream is not mistaken for a broken one.