fix latest data jitter bug

frontend/src/components/SvgGraph.vue

@@ -59,7 +59,9 @@ onUnmounted(() => {
     resize_observer.disconnect();
 });
 
-const now = useNow(33);
+const update_ms = 33;
+
+const now = useNow(update_ms);
 const window_duration = ref(props.initial_duration || 10 * 1000);
 
 const time_lines = [
@@ -234,7 +236,7 @@ const mouse_t = computed(() => {
 
 const show_data_at_time = computed(() => {
     if (mouse_t.value === null) {
-        return max_x.value;
+        return max_x.value + update_ms;
     } else {
         return mouse_t.value;
     }