The /proc fd monitor appends to one list for the module-scoped chamber,
and each episode asserted the whole history. So one hit failed its own
episode and also every later one: CI showed 6 WAL episodes red for a
single hit during lock_cancellation. Each episode now marks the list at
its start and only asserts the hits recorded after that mark.
Sabotage check (fix reverted, close-gap injection on): 1 of 10 WAL tests
fails, the one that caused the hit. The old harness failed 7.
c451cd1bba