feat: 스토리북에 토스트 루트 엘리먼트를 추가하는 데코레이터 적용

frontend/.storybook/preview.ts

@@ -0,0 +1,30 @@
+import type { Preview } from '@storybook/react';
+import { initialize, mswLoader } from 'msw-storybook-addon';
+import { storybookHandlers } from '../src/mocks/storybookHandlers';
+import { decorateGlobalStyle, decorateToastRoot } from './decorators';
+
+initialize({
+  serviceWorker: {
+    url: `${process.env.PUBLIC_URL}/mockServiceWorker.js`,
+  },
+  onUnhandledRequest: 'bypass',
+});
+
+const preview: Preview = {
+  decorators: [decorateGlobalStyle, decorateToastRoot],
+  parameters: {
+    actions: { argTypesRegex: '^on[A-Z].*' },
+    controls: {
+      matchers: {
+        color: /(background|color)$/i,
+        date: /Date$/,
+      },
+    },
+
+    msw: { handlers: [...storybookHandlers] },
+  },
+
+  loaders: [mswLoader],
+};
+
+export default preview;