The review's warning: while an open entry accumulates, the newline pre-checks in
the write path still charged a NEW entry's +3 cheap-bound overhead (quotes +
separator), so an exact-fit merged TAIL was truncated (or the pre-check
over-rejected it and flushed a truncated prefix). Both pre-checks now charge
the overhead only when no open entry is in progress, matching _push_locked's
open-aware bound. A regression case (the review's recipe: flush an open
fragment, then write one exact-fit newline-terminated line) is verified to
truncate when the +3 is restored.
The zh README's wire-contract section now describes the open flag like the en
side (the fd-3 Agent Note holds the split-billing arithmetic; a cross-doc link
was omitted to keep the bilingual link sequence aligned).
9194dfebc8