Destroy Chart.js instance on unmount in TimeframesFilter

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/components/Discover/Map/Filter/TimeframesFilter.vue

@@ -73,7 +73,7 @@
  *   duration range selectors.
  */
 
-import { ref, computed, watch, onMounted } from "vue";
+import { ref, computed, watch, onMounted, onBeforeUnmount } from "vue";
 import { storeToRefs } from "pinia";
 import { useAllMapDataStore } from "@/stores/allMapData";
 import { Chart, registerables } from "chart.js";
@@ -409,4 +409,9 @@ onMounted(() => {
   startTime.value = startMinDate.value;
   endTime.value = startMaxDate.value;
 });
+
+onBeforeUnmount(() => {
+  chart.value?.destroy();
+  chart.value = null;
+});
 </script>