chore: reorganize project into monorepo

frontend/src/components/interactive/BackToTop.svelte

@@ -0,0 +1,38 @@
+<script lang="ts">
+  import { onMount } from 'svelte';
+  import { fade } from 'svelte/transition';
+
+  let showButton = false;
+  const scrollThreshold = 300;
+
+  onMount(() => {
+    const handleScroll = () => {
+      showButton = window.scrollY > scrollThreshold;
+    };
+
+    window.addEventListener('scroll', handleScroll);
+    return () => window.removeEventListener('scroll', handleScroll);
+  });
+
+  function scrollToTop() {
+    window.scrollTo({
+      top: 0,
+      behavior: 'smooth'
+    });
+  }
+</script>
+
+{#if showButton}
+  <div 
+    class="fixed bottom-5 right-5 z-50"
+    transition:fade={{ duration: 200 }}
+  >
+    <button
+      on:click={scrollToTop}
+      class="flex items-center gap-1.5 px-3 py-2 rounded-lg border border-[var(--primary)] bg-[var(--primary-light)] text-[var(--primary)] hover:bg-[var(--primary)] hover:text-[var(--terminal-bg)] transition-all text-sm font-mono"
+    >
+      <i class="fas fa-arrow-up"></i>
+      <span>top</span>
+    </button>
+  </div>
+{/if}