feat(Footnote): add component for footnote text

src/shared/ui/Footnote/Footnote.stories.svelte

@@ -0,0 +1,31 @@
+<script module>
+import { defineMeta } from '@storybook/addon-svelte-csf';
+import Footnote from './Footnote.svelte';
+
+const { Story } = defineMeta({
+    title: 'Shared/Footnote',
+    tags: ['autodocs'],
+    parameters: {
+        docs: {
+            description: {
+                component: 'Styles footnote text',
+            },
+            story: { inline: false }, // Render stories in iframe for state isolation
+        },
+    },
+});
+</script>
+
+<Story name="Default">
+    <Footnote>
+        Footnote
+    </Footnote>
+</Story>
+
+<Story name="With custom render">
+    <Footnote>
+        {#snippet render({ class: className })}
+            <span class={className}>Footnote</span>
+        {/snippet}
+    </Footnote>
+</Story>

src/shared/ui/Footnote/Footnote.svelte

@@ -0,0 +1,30 @@
+<!--
+    Component: Footnote
+    Provides classes for styling footnotes
+-->
+<script lang="ts">
+import { cn } from '$shared/shadcn/utils/shadcn-utils';
+import type { Snippet } from 'svelte';
+
+interface Props {
+    children?: Snippet;
+    class?: string;
+    /**
+     * Custom render function for full control
+     */
+    render?: Snippet<[{ class: string }]>;
+}
+
+const { children, class: className, render }: Props = $props();
+
+const baseClasses = 'font-mono text-[0.5625rem] sm:text-[0.625rem] uppercase tracking-[0.2em] text-gray-500 opacity-60';
+const combinedClasses = cn(baseClasses, className);
+</script>
+
+{#if render}
+    {@render render({ class: combinedClasses })}
+{:else if children}
+    <span class={combinedClasses}>
+        {@render children()}
+    </span>
+{/if}