feat: add Storybook component explorer

src/lib/ui/components/IconButton.svelte

@@ -0,0 +1,44 @@
+<script lang="ts">
+  import IconGlyph from "./IconGlyph.svelte";
+
+  let {
+    icon,
+    label,
+    active = false,
+    disabled = false,
+  }: {
+    icon: string;
+    label: string;
+    active?: boolean;
+    disabled?: boolean;
+  } = $props();
+</script>
+
+<button class="icon-button" aria-label={label} data-active={active} {disabled}>
+  <IconGlyph name={icon} size="sm" />
+</button>
+
+<style>
+  .icon-button {
+    display: inline-grid;
+    width: 2.5rem;
+    height: 2.5rem;
+    place-items: center;
+    border: var(--ui-border);
+    background: rgba(2, 3, 2, 0.92);
+    color: var(--ui-color-muted);
+    cursor: pointer;
+    padding: 0;
+  }
+
+  .icon-button[data-active="true"],
+  .icon-button:hover {
+    border-color: var(--ui-color-accent);
+    color: var(--ui-color-accent);
+  }
+
+  .icon-button:disabled {
+    cursor: not-allowed;
+    opacity: 0.45;
+  }
+</style>