feat: add simple performance tracker

app/src/lib/performance/PerformanceViewer.svelte

@@ -0,0 +1,17 @@
+<script lang="ts">
+  import type { PerformanceStore } from ".";
+
+  export let store: PerformanceStore;
+
+  function getPerformanceData() {
+    return Object.entries($store.total).sort((a, b) => b[1] - a[1]);
+  }
+</script>
+
+{#if $store.runs.length !== 0}
+  {#each getPerformanceData() as [key, value]}
+    <p>{key}: {Math.floor(value * 100) / 100}ms</p>
+  {/each}
+{:else}
+  <p>No runs available</p>
+{/if}