feat: add token breakdown helpers

lib/detail-sort.ts

@@ -7,11 +7,11 @@ export interface DetailBreakdownItem {
 
 export type DetailBreakdownSortKey = "calls" | "total_tokens" | "quota";
 
-export function sortDetailBreakdown(
-  items: DetailBreakdownItem[],
+export function sortDetailBreakdown<T extends DetailBreakdownItem>(
+  items: T[],
   sortKey: DetailBreakdownSortKey,
   sortAsc: boolean
-): DetailBreakdownItem[] {
+): T[] {
   return [...items].sort((a, b) => {
     const diff = a[sortKey] - b[sortKey];
     if (diff !== 0) return sortAsc ? diff : -diff;