feat: Add aliases and new files for mocking in storybook

.storybook/main.ts

@@ -20,6 +20,7 @@ const config: StorybookConfig = {
       config.resolve.alias = {
         ...config.resolve.alias,
         '@': path.resolve(__dirname, '../'),
+        'next/headers': path.resolve(__dirname, '../app/utils/test/__mock__/next/headers.ts'),
       };
     }
     return config;

app/(sub-page)/sign-in/page.tsx

@@ -0,0 +1,11 @@
+import ContentContainer from '@/app/ui/view/atom/content-container';
+import SignInForm from '@/app/ui/user/sign-in-form/sign-in-form';
+
+// Refactor: fallback 스켈레톤으로 대체
+export default function Page() {
+  return (
+    <ContentContainer className="md:w-[768px]">
+      <SignInForm />
+    </ContentContainer>
+  );
+}

app/utils/test/__mock__/next/headers.ts

@@ -0,0 +1,6 @@
+export function cookies() {
+  return {
+    set: () => {},
+    get: () => {},
+  };
+}