The library card of an installed development build showed only the
installed version when the check had no answer, so a missing or failed
check looked like nothing to update. The card now says when the status
is unknown, when the check failed and when the add-on is up to date.
Add checker coverage for an install that recorded the channel name and
for a registry lookup that fails: neither reads as up to date.
Assisted-by: Claude:claude-sonnet-5-5