Initialize SvelteKit project with default routing, ESLint, Prettier, Storybook setup, and basic components.

src/stories/Header.svelte

@@ -0,0 +1,45 @@
+<script lang="ts">
+  import './header.css';
+  import Button from './Button.svelte';
+
+  interface Props {
+    user?: { name: string };
+    onLogin?: () => void;
+    onLogout?: () => void;
+    onCreateAccount?: () => void;
+  }
+
+  const { user, onLogin, onLogout, onCreateAccount }: Props = $props();
+</script>
+
+<header>
+  <div class="storybook-header">
+    <div>
+      <svg width="32" height="32" viewBox="0 0 32 32" xmlns="http://www.w3.org/2000/svg">
+        <g fill="none" fill-rule="evenodd">
+          <path
+            d="M10 0h12a10 10 0 0110 10v12a10 10 0 01-10 10H10A10 10 0 010 22V10A10 10 0 0110 0z"
+            fill="#FFF"
+          />
+          <path
+            d="M5.3 10.6l10.4 6v11.1l-10.4-6v-11zm11.4-6.2l9.7 5.5-9.7 5.6V4.4z"
+            fill="#555AB9"
+          />
+          <path d="M27.2 10.6v11.2l-10.5 6V16.5l10.5-6zM15.7 4.4v11L6 10l9.7-5.5z" fill="#91BAF8" />
+        </g>
+      </svg>
+      <h1>Acme</h1>
+    </div>
+    <div>
+      {#if user}
+        <span class="welcome">
+          Welcome, <b>{user.name}</b>!
+        </span>
+        <Button size="small" onclick={onLogout} label="Log out" />
+      {:else}
+        <Button size="small" onclick={onLogin} label="Log in" />
+        <Button primary size="small" onclick={onCreateAccount} label="Sign up" />
+      {/if}
+    </div>
+  </div>
+</header>