Function summarize 

pub fn summarize(
    corpus: &str,
    service: &str,
    records: &[TelemetryRecord],
) -> TelemetrySummary

Rolls a slice of telemetry records into a TelemetrySummary. Pure and DB-free (the reading is aggregate’s job): outcome bucketing, unit conversions (µs→ms, KiB→MiB), nearest-rank percentiles, per-phase P99, witnesses, and totals. skipped is left 0 — aggregate fills it from the read pass.