fix(traffic): сохранять точность объёмов и обозначать бинарные единицы

lib/fmt-rate.ts

@@ -10,10 +10,17 @@ export function fmtRate(v: number | null | undefined): string {
   return `${Math.round(v)} Мбит/с`
 }
 
-export function fmtGB(v: number | null | undefined): string {
-  if (v == null) return "—"
-  if (v >= 1000) return `${(v / 1000).toFixed(2)} ТБ`
-  return `${v.toFixed(1)} ГБ`
+const binaryFormatter = new Intl.NumberFormat("ru-RU", { maximumFractionDigits: 2 })
+/** Traffic API volumeUnit=GiB: preserve binary units and never format positive bytes as zero. */
+export function fmtGiB(v: number | null | undefined): string {
+  if (v == null || !Number.isFinite(v) || v < 0) return "—"
+  const bytes = v * 1024 ** 3
+  if (!Number.isFinite(bytes)) return "—"
+  if (bytes === 0) return "0 Б"
+  if (bytes < 1) return "<1 Б"
+  const units = ["Б", "КиБ", "МиБ", "ГиБ", "ТиБ", "ПиБ"]
+  const index = Math.min(units.length - 1, Math.floor(Math.log(bytes) / Math.log(1024)))
+  return `${binaryFormatter.format(bytes / 1024 ** index)} ${units[index]}`
 }
 
 export function formatBytes(n: number): string {