feat: add comprehensive authentication debug test suite

Add automated authentication testing infrastructure:

- AUTH-DEBUG-GUIDE.md: Complete guide for auth debugging
- auth-debug.spec.ts: Comprehensive auth flow validation tests
- playwright.auth.config.ts: Specialized config with extended timeouts
- auth-debug-setup.ts: Global test environment setup
- auth-debug-teardown.ts: Test cleanup and environment reset

Features:
- Admin user validation and permissions testing
- Email format validation including localhost domains
- User registration and OAuth integration testing
- Database connectivity and session management
- Password security and error handling validation
- Cross-browser testing with mobile support
- Enhanced reporting and interactive debugging
- CI/CD integration with artifacts and JUnit reports

Replaces manual browser console debugging scripts with
automated, cross-browser E2E tests for better reliability
and maintainability.

tests/e2e/playwright.auth.config.ts

@@ -0,0 +1,158 @@
+import { defineConfig, devices } from '@playwright/test';
+
+/**
+ * Specialized Playwright configuration for authentication debug tests
+ * Optimized for debugging auth flows with extended timeouts and detailed reporting
+ */
+export default defineConfig({
+  testDir: './tests/e2e',
+  testMatch: '**/auth-debug.spec.ts',
+
+  /* Run tests in files in parallel */
+  fullyParallel: false, // Auth tests should run sequentially to avoid conflicts
+
+  /* Fail the build on CI if you accidentally left test.only in the source code. */
+  forbidOnly: !!process.env.CI,
+
+  /* Retry on CI only */
+  retries: process.env.CI ? 2 : 0,
+
+  /* Opt out of parallel tests on CI. */
+  workers: process.env.CI ? 1 : 1, // Auth tests work better with single worker
+
+  /* Reporter to use. See https://playwright.dev/docs/test-reporters */
+  reporter: [
+    ['html', { outputFolder: 'playwright-report-auth' }],
+    ['json', { outputFile: 'playwright-report-auth.json' }],
+    ['list'],
+    ['junit', { outputFile: 'playwright-auth-results.xml' }],
+  ],
+
+  /* Shared settings for all the projects below. */
+  use: {
+    /* Base URL to use in actions like `await page.goto('/')`. */
+    baseURL: 'http://localhost:8080',
+
+    /* Collect trace when retrying the failed test. */
+    trace: 'retain-on-failure',
+
+    /* Take screenshot on failure */
+    screenshot: 'only-on-failure',
+
+    /* Record video on failure */
+    video: 'retain-on-failure',
+
+    /* Extended timeouts for auth operations */
+    actionTimeout: 15000,
+    navigationTimeout: 30000,
+
+    /* Ignore HTTPS errors */
+    ignoreHTTPSErrors: true,
+
+    /* Accept downloads */
+    acceptDownloads: false,
+
+    /* Viewport settings */
+    viewport: { width: 1280, height: 720 },
+
+    /* Locale for testing */
+    locale: 'en-US',
+
+    /* Timezone for consistent testing */
+    timezoneId: 'America/New_York',
+  },
+
+  /* Configure projects for major browsers */
+  projects: [
+    {
+      name: 'auth-debug-chromium',
+      use: {
+        ...devices['Desktop Chrome'],
+        // Additional Chrome flags for debugging
+        launchOptions: {
+          args: [
+            '--disable-web-security',
+            '--disable-features=VizDisplayCompositor',
+            '--no-sandbox',
+            '--disable-dev-shm-usage',
+          ],
+        },
+      },
+    },
+
+    {
+      name: 'auth-debug-firefox',
+      use: {
+        ...devices['Desktop Firefox'],
+        // Firefox specific settings
+        launchOptions: {
+          firefoxUserPrefs: {
+            'security.tls.insecure_fallback_hosts': 'localhost',
+            'network.stricttransportsecurity.preloadlist': false,
+          },
+        },
+      },
+    },
+
+    {
+      name: 'auth-debug-webkit',
+      use: { ...devices['Desktop Safari'] },
+    },
+
+    /* Test against mobile viewports for responsive auth */
+    {
+      name: 'auth-debug-mobile-chrome',
+      use: { ...devices['Pixel 5'] },
+    },
+    {
+      name: 'auth-debug-mobile-safari',
+      use: { ...devices['iPhone 12'] },
+    },
+  ],
+
+  /* Global setup and teardown */
+  globalSetup: require.resolve('./auth-debug-setup.ts'),
+  globalTeardown: require.resolve('./auth-debug-teardown.ts'),
+
+  /* Test timeout for auth operations */
+  timeout: 60000, // 1 minute per test
+  expect: {
+    timeout: 10000, // 10 seconds for assertions
+  },
+
+  /* Run your local dev server before starting the tests */
+  webServer: [
+    {
+      command: 'bun run dev',
+      port: 8080,
+      timeout: 120000,
+      reuseExistingServer: !process.env.CI,
+      stdout: 'pipe',
+      stderr: 'pipe',
+      env: {
+        NODE_ENV: 'test',
+        VITE_COUCHDB_URL: 'http://localhost:5984',
+        VITE_COUCHDB_USERNAME: 'admin',
+        VITE_COUCHDB_PASSWORD: 'password',
+      },
+    },
+    {
+      command: 'docker-compose -f docker/docker-compose.yaml up -d',
+      timeout: 60000,
+      reuseExistingServer: !process.env.CI,
+    },
+  ],
+
+  /* Output directories */
+  outputDir: 'test-results-auth/',
+
+  /* Metadata for reporting */
+  metadata: {
+    testType: 'Authentication Debug',
+    environment: process.env.NODE_ENV || 'test',
+    version: process.env.APP_VERSION || 'development',
+    author: 'Medication Reminder App Team',
+    description:
+      'Comprehensive authentication flow debugging and validation tests',
+  },
+});