Drop the rejected tail of a verify block of block positions that one
concat write appended, keeping accepted: a recurrence restores its
pre-round snapshot and bit-exactly replays the accepted prefix; other storage
trims the rest. A plain ring stops being trimmable once it wraps, but the
block was one concat write that keeps the newest window-1 positions plus the
block in temporal order, so its rollback trim drops the tail physically
(at least the window remains: accepted >= 1).
Drop the rejected tail of a verify block of
blockpositions that one concat write appended, keepingaccepted: a recurrence restores its pre-round snapshot and bit-exactly replays the accepted prefix; other storage trims the rest. A plain ring stops being trimmable once it wraps, but the block was one concat write that keeps the newest window-1 positions plus the block in temporal order, so its rollback trim drops the tail physically (at least the window remains:accepted>= 1).