fix(test): remove isolate false to fix cross-file DOM leakage in CI

vitest.config.mts

@@ -15,8 +15,6 @@ export default defineConfig({
     test: {
         environment: 'happy-dom',
         globals: true,
-        isolate: false,
-        css: false,
         exclude: ['**/node_modules/**', '**/.next/**', '**/dist/**', '**/*.e2e.test.ts'],
         include: ['**/*.test.{ts,tsx}'],
         coverage: {