Add Axe accessibility E2E tests

e2e/models/UserPage.ts

@@ -0,0 +1,15 @@
+import { Base } from './Base'
+
+export class UserPage extends Base {
+  async goTo(handle: string) {
+    await this.navigateTo(`/${handle}`)
+  }
+
+  async openPostDetails(postText: string) {
+    await this.page
+      .getByRole('article')
+      .filter({ hasText: postText })
+      .getByRole('link', { name: '詳細・スレッド' })
+      .click()
+  }
+}