fix(traffic): проверять live-срез и прекращать опрос выключенных устройств

docs/ux-ui/acceptance/traffic-live-interop-2026-10-12.json

@@ -0,0 +1,10 @@
+{
+  "date": "2026-10-12",
+  "block": "12.5.179",
+  "newFrontend": "ux-live179",
+  "oldBackend": "ux-history178",
+  "readerAccepted": true,
+  "serverCount": 2,
+  "pageErrors": 0,
+  "bound": "Additive observed DTO reader compatibility; legacy numeric-only paths verified separately as unknown"
+}