Function derive_usage

src/sessions/transcript_backfill.rs:393–400

Per-provider usage derivation (Codex's event-attached usage is handled in [`derive_line_facts`] instead, because it lives on a *different* line).

(provider: &str, record: &Value)

/// Per-provider usage derivation (Codex's event-attached usage is handled in
/// [`derive_line_facts`] instead, because it lives on a *different* line).
fn derive_usage(provider: &str, record: &Value) -> Option<Value> {
    match provider {
        "claude" => usage_counters_from(record.get("message").unwrap_or(record)),
        "cursor" | "vibe" => usage_counters_from(record)
            .or_else(|| record.get("message").and_then(usage_counters_from)),
        _ => None,
    }
}