Function scan_shard 

pub fn scan_shard(
    content: &[u8],
    range_start: usize,
    range_end: usize,
) -> (ShardRecords, Option<usize>)

scan_shard_with_refusals without the refusal offsets.

A shard’s refusal list is only meaningful next to the stitch that decides which of the shard’s bytes were kept, so this convenience wrapper is for callers that build no index from the result (the parity tests) — a caller that DOES must take the offsets and attribute them, or it reports refusals that no retained record produced.