Function split_conduit_highlight_counts 

pub(super) async fn split_conduit_highlight_counts(
    services: &Services,
) -> Result

Splits a Conduit database’s conflated highlight-count column once.

Conduit aliased roomuserid_lastnotificationread onto the userroomid_highlightcount tree, so one column holds both stores; tuwunel keeps them apart. Gated on its own marker; the split itself returns early unless a room-keyed row is present, so it is a cheap no-op on a native database.