Enhance auth flows and improve e2e test reliability

- Remove redundant `'use client'` directives in auth pages to streamline code.
- Refine Playwright config: adjust worker limits and add video recording for failed tests.
- Improve session management in e2e tests with isolated state clearing, console log collection, and detailed failure attachments.
- Update API client: better handle auth routes, ensure safe token refresh, and prevent unnecessary redirects.

frontend/e2e/auth-login.spec.ts

@@ -1,11 +1,81 @@
 import { test, expect } from '@playwright/test';
 
 test.describe('Login Flow', () => {
-  test.beforeEach(async ({ page }) => {
+  test.describe.configure({ mode: 'serial' });
+
+  // Collect browser console logs per test for debugging
+  let consoleLogs: string[] = [];
+
+  test.beforeEach(async ({ page, context }) => {
+    consoleLogs = [];
+
+    // Capture console logs
+    page.on('console', (msg) => {
+      try {
+        consoleLogs.push(`[${msg.type()}] ${msg.text()}`);
+      } catch {
+        // ignore
+      }
+    });
+
+    // Ensure clean state across parallel workers
+    await context.clearCookies();
+    await page.addInitScript(() => {
+      try {
+        localStorage.clear();
+        sessionStorage.clear();
+      } catch {}
+    });
+
     // Navigate to login page before each test
     await page.goto('/login');
   });
 
+  test.afterEach(async ({ page }, testInfo) => {
+    if (testInfo.status !== 'passed') {
+      // Attach current URL
+      await testInfo.attach('page-url.txt', {
+        body: page.url(),
+        contentType: 'text/plain',
+      });
+
+      // Attach skeleton count to see if page stuck on loading state
+      try {
+        const skeletonCount = await page.locator('.animate-pulse').count();
+        await testInfo.attach('skeleton-count.txt', {
+          body: String(skeletonCount),
+          contentType: 'text/plain',
+        });
+      } catch {}
+
+      // Attach full DOM snapshot
+      try {
+        const html = await page.content();
+        await testInfo.attach('dom.html', {
+          body: html,
+          contentType: 'text/html',
+        });
+      } catch {}
+
+      // Attach full page screenshot
+      try {
+        const img = await page.screenshot({ fullPage: true });
+        await testInfo.attach('screenshot.png', {
+          body: img,
+          contentType: 'image/png',
+        });
+      } catch {}
+
+      // Attach console logs
+      try {
+        await testInfo.attach('console.log', {
+          body: consoleLogs.join('\n'),
+          contentType: 'text/plain',
+        });
+      } catch {}
+    }
+  });
+
   test('should display login form', async ({ page }) => {
     // Check page title
     await expect(page.locator('h2')).toContainText('Sign in to your account');

frontend/e2e/auth-register.spec.ts

@@ -1,11 +1,81 @@
 import { test, expect } from '@playwright/test';
 
 test.describe('Registration Flow', () => {
-  test.beforeEach(async ({ page }) => {
+  test.describe.configure({ mode: 'serial' });
+
+  // Collect browser console logs per test for debugging
+  let consoleLogs: string[] = [];
+
+  test.beforeEach(async ({ page, context }) => {
+    consoleLogs = [];
+
+    // Capture console logs
+    page.on('console', (msg) => {
+      try {
+        consoleLogs.push(`[${msg.type()}] ${msg.text()}`);
+      } catch {
+        // ignore
+      }
+    });
+
+    // Ensure clean state across parallel workers
+    await context.clearCookies();
+    await page.addInitScript(() => {
+      try {
+        localStorage.clear();
+        sessionStorage.clear();
+      } catch {}
+    });
+
     // Navigate to register page before each test
     await page.goto('/register');
   });
 
+  test.afterEach(async ({ page }, testInfo) => {
+    if (testInfo.status !== 'passed') {
+      // Attach current URL
+      await testInfo.attach('page-url.txt', {
+        body: page.url(),
+        contentType: 'text/plain',
+      });
+
+      // Attach skeleton count to see if page stuck on loading state
+      try {
+        const skeletonCount = await page.locator('.animate-pulse').count();
+        await testInfo.attach('skeleton-count.txt', {
+          body: String(skeletonCount),
+          contentType: 'text/plain',
+        });
+      } catch {}
+
+      // Attach full DOM snapshot
+      try {
+        const html = await page.content();
+        await testInfo.attach('dom.html', {
+          body: html,
+          contentType: 'text/html',
+        });
+      } catch {}
+
+      // Attach full page screenshot
+      try {
+        const img = await page.screenshot({ fullPage: true });
+        await testInfo.attach('screenshot.png', {
+          body: img,
+          contentType: 'image/png',
+        });
+      } catch {}
+
+      // Attach console logs
+      try {
+        await testInfo.attach('console.log', {
+          body: consoleLogs.join('\n'),
+          contentType: 'text/plain',
+        });
+      } catch {}
+    }
+  });
+
   test('should display registration form', async ({ page }) => {
     // Check page title
     await expect(page.locator('h2')).toContainText('Create your account');

frontend/playwright.config.ts

@@ -17,8 +17,8 @@ export default defineConfig({
   forbidOnly: !!process.env.CI,
   /* Retry on CI and locally to handle flaky tests */
   retries: process.env.CI ? 2 : 1,
-  /* Limit workers to prevent test interference */
-  workers: process.env.CI ? 1 : 12,
+  /* Limit workers to prevent test interference and Next dev server overload */
+  workers: process.env.CI ? 1 : 8,
   /* Reporter to use. See https://playwright.dev/docs/test-reporters */
   reporter: process.env.CI ? 'github' : 'list',
   /* Suppress console output unless VERBOSE=true */
@@ -31,6 +31,8 @@ export default defineConfig({
     trace: 'on-first-retry',
     /* Screenshot on failure */
     screenshot: 'only-on-failure',
+    /* Record video for failed tests to diagnose flakiness */
+    video: 'retain-on-failure',
   },
 
   /* Configure projects for major browsers */

frontend/src/app/(auth)/login/page.tsx

@@ -1,5 +1,3 @@
-'use client';
-
 import dynamic from 'next/dynamic';
 
 // Code-split LoginForm - heavy with react-hook-form + validation

frontend/src/app/(auth)/password-reset/page.tsx

@@ -3,8 +3,6 @@
  * Users enter their email to receive reset instructions
  */
 
-'use client';
-
 import dynamic from 'next/dynamic';
 
 // Code-split PasswordResetRequestForm

frontend/src/app/(auth)/register/page.tsx

@@ -1,5 +1,3 @@
-'use client';
-
 import dynamic from 'next/dynamic';
 
 // Code-split RegisterForm (313 lines)

frontend/src/lib/api/client.ts

@@ -95,17 +95,18 @@ async function refreshAccessToken(): Promise<string> {
         console.error('[API Client] Token refresh failed:', error);
       }
 
-      // Clear auth and redirect to login
+      // Clear auth state
       const authStore = await getAuthStore();
       await authStore.clearAuth();
 
-      // Redirect to login if we're in browser
+      // Only redirect to login when not already on an auth route
       if (typeof window !== 'undefined') {
         const currentPath = window.location.pathname;
-        const returnUrl = currentPath !== '/login' && currentPath !== '/register'
-          ? `?returnUrl=${encodeURIComponent(currentPath)}`
-          : '';
-        window.location.href = `/login${returnUrl}`;
+        const onAuthRoute = currentPath === '/login' || currentPath === '/register' || currentPath.startsWith('/password-reset');
+        if (!onAuthRoute) {
+          const returnUrl = currentPath ? `?returnUrl=${encodeURIComponent(currentPath)}` : '';
+          window.location.href = `/login${returnUrl}`;
+        }
       }
 
       throw error;
@@ -129,8 +130,12 @@ client.instance.interceptors.request.use(
     const authStore = await getAuthStore();
     const { accessToken } = authStore;
 
-    // Add Authorization header if token exists
-    if (accessToken && requestConfig.headers) {
+    // Do not attach Authorization header for auth endpoints
+    const url = requestConfig.url || '';
+    const isAuthEndpoint = url.includes('/auth/login') || url.includes('/auth/register') || url.includes('/auth/refresh') || url.includes('/auth/password') || url.includes('/password');
+
+    // Add Authorization header if token exists and not hitting auth endpoints
+    if (accessToken && requestConfig.headers && !isAuthEndpoint) {
       requestConfig.headers.Authorization = `Bearer ${accessToken}`;
     }
 
@@ -170,13 +175,27 @@ client.instance.interceptors.response.use(
 
     // Handle 401 Unauthorized - Token expired
     if (error.response?.status === 401 && originalRequest && !originalRequest._retry) {
+      const url = originalRequest.url || '';
+      const isAuthEndpoint = url.includes('/auth/login') || url.includes('/auth/register') || url.includes('/auth/password') || url.includes('/password');
+
+      // If the 401 is from auth endpoints, do not attempt refresh
+      if (isAuthEndpoint) {
+        return Promise.reject(error);
+      }
+
       // If refresh endpoint itself fails with 401, clear auth and reject
-      if (originalRequest.url?.includes('/auth/refresh')) {
+      if (url.includes('/auth/refresh')) {
         const authStore = await getAuthStore();
         await authStore.clearAuth();
         return Promise.reject(error);
       }
 
+      // Ensure we have a refresh token before attempting refresh
+      const authStore = await getAuthStore();
+      if (!authStore.refreshToken) {
+        return Promise.reject(error);
+      }
+
       originalRequest._retry = true;
 
       try {