chore: basic storybook coverage for shared/ui components

src/shared/ui/ContentEditable/ContentEditable.stories.svelte

@@ -0,0 +1,22 @@
+<script module>
+import { defineMeta } from '@storybook/addon-svelte-csf';
+import ContentEditable from './ContentEditable.svelte';
+
+const { Story } = defineMeta({
+    title: 'Shared/ContentEditable',
+    tags: ['autodocs'],
+    parameters: {
+        docs: {
+            story: { inline: false }, // Render stories in iframe for state isolation
+        },
+    },
+});
+</script>
+
+<script lang="ts">
+let value = $state('Here we can type and edit the content. Try it!');
+</script>
+
+<Story name="Default">
+    <ContentEditable bind:text={value} />
+</Story>