fix(uptime): отличать ошибки опроса от измеренных потерь Ping

docs/ux-ui/acceptance/ping-measurement-interop-2026-10-12.json

@@ -0,0 +1,9 @@
+{
+  "date": "2026-10-12",
+  "block": "12.5.173",
+  "newFrontend": "ux-ping173",
+  "oldBackend": "ux-history172",
+  "readerAccepted": true,
+  "probeCount": 0,
+  "bound": "Actual empty configured catalog; nonempty old valid payloads separately covered by unit/UI fixtures"
+}