fn already_kept(seen: &mut HashSet<String>, uuid: &str) -> boolExpand description
Whether this read has already kept a row under uuid.
The key a re-appended block is deduped by. A transcript can carry a
block of records twice: the copies share uuid, type and the message
content, and may differ in metadata fields (slug, promptId, a zeroed
usage). uuid is what names the pair, and a row with no uuid names
nothing to dedupe on and is never a repeat.