feat(*): Add initial scaffolding

src/routes/upload/+page.svelte

@@ -0,0 +1,12 @@
+<script lang="ts">
+// Upload logic will go here
+</script>
+
+<section class="max-w-xl mx-auto py-12">
+  <h1 class="text-2xl font-bold mb-4">Upload Student Submissions</h1>
+  <p class="mb-6">Upload student assignments for instant AI-powered assessment and feedback.</p>
+  <form>
+    <!-- File or text input UI will go here -->
+    <button class="btn btn-primary mt-4" type="submit" disabled>Upload (Coming soon)</button>
+  </form>
+</section>