fix(traffic): сохранять историю и показывать достоверную свежесть

tests/e2e/traffic-live.spec.ts

@@ -1,15 +1,16 @@
+import { observedTrafficFixturePayload } from "./traffic-observation-fixture"
 import { installOpenLiveStream, resumeLiveStream, sendLiveHeartbeat } from "./live-stream-fixture"
 import { test, expect } from '@playwright/test'
 
 for (const variant of ['closed', 'invalid', 'http-error', 'silent', 'awaiting'] as const) {
   test(`Трафик: SSE ${variant} не выдаёт старое измерение за live`, async ({ page }) => {
     const server = { id: '1', name: 'Тестовый сервер', site: 'TEST', country: 'RU', status: 'online', rxNow: 2, txNow: 3, rxPeak: 5, txPeak: 6, rxTotal: 100, txTotal: 200, sessions: 1, rxSeries: [1, 2], txSeries: [2, 3] }
-    await page.route('**/health', route => route.fulfill({ json: { ok: true } }))
+    await page.route('**/health', route => route.fulfill({ json: observedTrafficFixturePayload({ ok: true }) }))
     await page.route('**/api/**', route => {
       const url = new URL(route.request().url())
       const path = url.pathname
       if (path.endsWith('/live')) {
-        if (variant === 'http-error' || url.searchParams.get('iface') === 'ether2') return route.fulfill({ status: 503, json: { error: 'Поток недоступен' } })
+        if (variant === 'http-error' || url.searchParams.get('iface') === 'ether2') return route.fulfill({ status: 503, json: observedTrafficFixturePayload({ error: 'Поток недоступен' }) })
         const sample = { rxMbps: 17, txMbps: 19, at: '2026-09-23T12:00:00Z' }
         const body = 'event: sample\ndata: ' + JSON.stringify(sample) + '\n\n' + (variant === 'invalid' ? 'event: sample\ndata: {"rxMbps":null,"txMbps":-1}\n\n' : '')
         return route.fulfill({ contentType: 'text/event-stream', body })
@@ -21,7 +22,7 @@ for (const variant of ['closed', 'invalid', 'http-error', 'silent', 'awaiting']
         : path.endsWith('/interfaces') || path === '/api/traffic/bound-interfaces' ? { interfaces: [] }
         : path === '/api/traffic/users' ? { users: [] }
         : path === '/api/servers' ? [] : {}
-      return route.fulfill({ json })
+      return route.fulfill({ json: observedTrafficFixturePayload(json) })
     })
     if (variant === 'silent' || variant === 'awaiting') await installOpenLiveStream(page, '/api/traffic/servers/1/live', { rxMbps: 17, txMbps: 19, at: '2026-09-23T12:00:00Z' }, variant !== 'awaiting')
     const received = new Date('2026-09-28T06:00:00Z')