feat: add Storybook component explorer

src/lib/ui/components/DashboardHeader.svelte

@@ -0,0 +1,71 @@
+<script lang="ts">
+  import type { UiModuleBlock } from "../types";
+  import ModuleCard from "./ModuleCard.svelte";
+
+  let {
+    title,
+    subtitle,
+    eyebrow,
+    module,
+  }: {
+    title: string;
+    subtitle?: string;
+    eyebrow?: string;
+    module?: UiModuleBlock;
+  } = $props();
+
+  const titleId = $props.id();
+</script>
+
+<header class="dashboard-header" aria-labelledby={titleId}>
+  <div>
+    {#if eyebrow}
+      <p>{eyebrow}</p>
+    {/if}
+    <h1 id={titleId}>{title}</h1>
+    {#if subtitle}
+      <span>{subtitle}</span>
+    {/if}
+  </div>
+  {#if module}
+    <ModuleCard {module} />
+  {/if}
+</header>
+
+<style>
+  .dashboard-header {
+    display: grid;
+    grid-template-columns: minmax(0, 1fr) auto;
+    gap: var(--ui-space-4);
+    align-items: start;
+    border-bottom: var(--ui-border);
+    padding: var(--ui-space-3);
+  }
+
+  p,
+  span,
+  h1 {
+    margin: 0;
+    text-transform: uppercase;
+  }
+
+  p,
+  span {
+    color: var(--ui-color-muted);
+    font-size: 0.78rem;
+    font-weight: 800;
+  }
+
+  h1 {
+    overflow-wrap: anywhere;
+    font-family: var(--ui-font-display);
+    font-size: clamp(2.45rem, 5vw, 4.2rem);
+    line-height: 0.85;
+  }
+
+  @media (max-width: 780px) {
+    .dashboard-header {
+      grid-template-columns: 1fr;
+    }
+  }
+</style>