The review's warning: the en README's inner 'Wire contract' section still
described only the truncated flag while the zh counterpart (and the outer 'The
wire' section) described open. The inner en section now matches. The exact-fit
closing-line case comment described the buffered-chunks pre-check recipe while
the program actually drives the scan pre-check; the comment now states the
actual arithmetic and path (and the buffered variant was dropped — its writes
coalesce into one call in the test environment, so it did not discriminate).