Function scan_shard_with_refusals 

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

[scan_shard_with_diagnostics] without the malformed-record offset.

Kept as its own 3-tuple-returning function — not folded into [scan_shard_with_diagnostics] in place — because it is public on a published crate and adding a return value in place would be a breaking change (the same reasoning crate::scan_shard_classified documents for staying a 3-tuple after #3395 added refusal offsets).