savesAndLoadsLeaderForTerm_atPlausibilityEdges

The savesAndLoadsTerm_atPlausibilityEdges argument, applied to the pin's term: it is compared for equality with currentTerm, which the engine admits anywhere in 0..MAX_PLAUSIBLE. A term column that cannot hold a Long therefore does not merely round-trip a slightly different number — it makes the pin permanently invisible at the one term it was written for, and §3.10 transfer to that node fails on its auto-timeout with nothing to point at.

0 is included because it is a real term for this record even though no leader is ever established at term 0: an adapter that encodes absence as a 0 sentinel fails leaderForTermBeforeAnySave_isNull and this together.