Function attribute_round 

pub fn attribute_round(
    report: &AbReport,
    read_events: impl Fn(&str) -> Option<String>,
    min_occurrences: usize,
) -> RoundAttribution

Attribute the treatment-arm losses in report. read_events(path) returns the event-log JSONL for a transcript path (live: read the file; tests: an in-memory map). Only paired-scorable native losses are attributed — an infra failure is not a harness lesson. Interventions from a layer that defers elsewhere (is_evolution_actionable false) still mark a loss as addressed but are dropped from the fixer feed.