fix(ui): снимать статус live при отсутствии обновлений

hooks/use-flow-live.ts

@@ -37,7 +37,10 @@ export function useFlowLive(opts: {
   useEffect(() => {
     if (!opts.enabled) return
     const ac = new AbortController()
+    let sampleTimer: ReturnType<typeof setTimeout> | undefined
+    const stopTimer = () => clearTimeout(sampleTimer)
     const setError = (error: string) => {
+      stopTimer()
       if (!ac.signal.aborted) setResult(previous => ({ key, sample: previous?.key === key ? previous.sample : null, receivedAt: previous?.key === key ? previous.receivedAt : null, error }))
     }
     const path = `/api/traffic/flow/live${flowQuery({
@@ -50,6 +53,12 @@ export function useFlowLive(opts: {
       excludeOverlay: opts.excludeOverlay,
     })}`
     const url = resolveApiUrl(opts.backendUrl, path)
+    // Backend ticks every 1.5–2s; tolerate several missed samples. Heartbeats do not reset this timer.
+    const awaitSample = () => {
+      stopTimer()
+      sampleTimer = setTimeout(() => setError("Нет обновлений live более 15 секунд"), 15_000)
+    }
+    awaitSample()
 
     let buf = ""
 
@@ -82,6 +91,7 @@ export function useFlowLive(opts: {
               if (!isValidFlowLiveSample(parsed)) {
                 throw new Error("Некорректные данные live-потока")
               }
+              awaitSample()
               setResult({ key, sample: parsed, receivedAt: Date.now(), error: parsed.degraded ? "Коллектор перегружен: упрощённая аналитика" : null })
             } else if (ev.event === "error" && ev.data) {
               const parsed: unknown = JSON.parse(ev.data)
@@ -93,10 +103,12 @@ export function useFlowLive(opts: {
         if (ac.signal.aborted) return
         setError(e instanceof Error ? e.message : "Ошибка live-потока")
         ac.abort()
+      } finally {
+        stopTimer()
       }
     })()
 
-    return () => ac.abort()
+    return () => { stopTimer(); ac.abort() }
   }, [opts.enabled, opts.backendUrl, opts.range, opts.serverId, opts.userId, opts.iface, opts.dedup, opts.excludeMesh, opts.excludeOverlay, key])
 
   return result?.key === key ? { sample: result.sample, error: result.error, receivedAt: result.receivedAt } : { sample: null, error: null, receivedAt: null }