Function family 

async fn family(
    services: &Services,
    forward: &'static str,
    reverse: &'static str,
    counter: u64,
    words: usize,
) -> (Family, Vec<u64>)

Scans one family in two passes, and a third only where the bitmaps disagree.

The reverse bitmap completes before the forward stream begins, so a concurrent allocation surfaces only forward-side and cannot be counted dangling or stale. The third pass names each loser and its identity; on a clean family the bitmap difference proves there are none, so it never runs. Returns the family and its reverse-key bitmap, which the deep sweep reuses to detect orphaned statediff entries.