Function journal_migration_with_cursor 

pub fn journal_migration_with_cursor(
    tx: &Connection,
    tag: &str,
    checksum: Option<&str>,
    content_checksum: &str,
    run_id: Option<&str>,
    statements: &str,
    cursor: Option<&str>,
    applied_at: i64,
) -> Result<(), BookkeepingError>

journal_migration with the host’s exact commit cursor written in the same transaction. WAL2 authorities know their next TxId before COMMIT and use this form; HCTree keeps using the run-id form and resolves/backfills its engine-assigned cursor after commit.