feat: implement tunnel quality polling and service monitor tuning to 1s/30s intervals

go-backend/internal/http/handler/monitoring.go

@@ -744,6 +744,16 @@ func (h *Handler) monitorServiceLatestResultsHandler(w http.ResponseWriter, r *h
 		return
 	}
 
+	// Try in-memory cache first (updated every 1s)
+	if h.healthCheck != nil {
+		cached := h.healthCheck.GetLatestCached()
+		if len(cached) > 0 {
+			response.WriteJSON(w, response.OK(cached))
+			return
+		}
+	}
+
+	// Fallback to database
 	results, err := h.repo.GetLatestServiceMonitorResults()
 	if err != nil {
 		response.WriteJSON(w, response.Err(-2, err.Error()))