Reverting chain start-up, node schema reading and decode to log.failed left all
420 tests green -- so the fix was pinned in three of six places and free to rot
in the other three. Testing log.broke on its own never covers this: what recurs
is a call SITE reaching for the wrong function, and a unit test of the right one
passes either way. Each site is now exercised through the code that logs.
One finding, confirmed, and proven by reverting each site in turn.
