Fix admin routing and Playwright smoke checks

tests/e2e/blog-crud.spec.ts

@@ -1,4 +1,5 @@
 import { expect, test } from '@playwright/test';
+import { loginThroughAdminUi } from './helpers/admin-auth';
 
 const username = process.env.E2E_ADMIN_USERNAME ?? 'admin';
 const password = process.env.E2E_ADMIN_PASSWORD;
@@ -8,17 +9,10 @@ test.describe('blog CRUD operations', () => {
   test('complete blog creation, read, update, delete flow', async ({ page }) => {
     test.skip(!password, 'E2E_ADMIN_PASSWORD is required.');
 
-    // localStorage 초기화 (이전 테스트의 상태 제거)
     await page.goto(`${baseUrl}/admin/login`);
     await page.evaluate(() => localStorage.clear());
 
-    // 1. 로그인
-    await page.locator('input[name="username"]').fill(username);
-    await page.locator('input[name="password"]').fill(password);
-    await page.getByRole('button', { name: '로그인' }).click();
-
-    // 대시보드로 리다이렉트 대기 (더 긴 타임아웃)
-    await page.waitForURL('**/admin/dashboard', { timeout: 30_000 });
+    await loginThroughAdminUi(page, baseUrl, username, password);
     console.log('✓ Logged in and redirected to dashboard');
     
     // 2. 블로그 페이지로 이동