Function compute_postpone_follow_through 

fn compute_postpone_follow_through(
    events: &[LoggedEvent],
    range_start: DateTime<Local>,
    now: DateTime<Local>,
) -> PostponeFollowThrough

For every BreakPostponed event inside [range_start, now], look forward in the (chronologically ordered) event stream for the next BreakEnd or BreakSkipped of the same kind and bucket the outcome. Intervening postpones of the same kind don’t resolve — we keep scanning. A postpone with no later resolution in the log counts as unresolved.