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

lib/fmt-rate.test.ts

@@ -1,6 +1,11 @@
 import assert from "node:assert/strict"
-import { fmtRate } from "./fmt-rate.js"
+import { fmtRate, fmtGiB } from "./fmt-rate.js"
 assert.equal(fmtRate(null),"—");assert.equal(fmtRate(undefined),"—");assert.equal(fmtRate(0),"0 Кбит/с")
 assert.equal(fmtRate(0.000001),"<1 Кбит/с");assert.equal(fmtRate(0.001),"1 Кбит/с")
 assert.equal(fmtRate(1),"1.00 Мбит/с");assert.equal(fmtRate(1000),"1.00 Гбит/с")
 console.log("rate formatting unknown/zero/positive-small/units tests ok")
+assert.equal(fmtGiB(null),"—");assert.equal(fmtGiB(0),"0 Б")
+assert.equal(fmtGiB(1/1024**3),"1 Б");assert.equal(fmtGiB(1/1024**2),"1 КиБ")
+assert.equal(fmtGiB(1/1024),"1 МиБ");assert.equal(fmtGiB(1),"1 ГиБ");assert.equal(fmtGiB(1024),"1 ТиБ")
+assert.equal(fmtGiB(100/1024),"100 МиБ");assert.equal(fmtGiB(Number.MAX_VALUE),"—")
+console.log("binary traffic volume precision/unit boundary tests ok")