test(e2e): add 14 new web E2E test files for critical user flows

Cover auth (login, register, OAuth callbacks), search with filters,
listing detail, dashboard, analytics, create listing form, admin
dashboard/users/moderation/KYC, navigation routing, and responsive
design. Total 91 test cases using Playwright with API route mocking.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

e2e/web/auth-oauth-callback.spec.ts

@@ -0,0 +1,57 @@
+import { test, expect } from '@playwright/test';
+
+test.describe('OAuth Callback Pages', () => {
+  test.describe('Google callback', () => {
+    test('shows loading state while processing', async ({ page }) => {
+      // Intercept token exchange to keep it pending
+      await page.route('**/auth/google/callback**', (route) =>
+        new Promise(() => {
+          // Never resolve — keeps loading state visible
+        }),
+      );
+
+      await page.goto('/auth/callback/google?code=test-code');
+      // Should show a loading/spinner state
+      await expect(page.locator('.animate-spin').first()).toBeVisible({ timeout: 5000 });
+    });
+
+    test('redirects to login with error on failure', async ({ page }) => {
+      await page.route('**/auth/google/callback**', (route) =>
+        route.fulfill({
+          status: 401,
+          contentType: 'application/json',
+          body: JSON.stringify({ message: 'OAuth failed' }),
+        }),
+      );
+
+      await page.goto('/auth/callback/google?code=bad-code');
+      await expect(page).toHaveURL(/\/login\?error=/, { timeout: 10000 });
+    });
+  });
+
+  test.describe('Zalo callback', () => {
+    test('shows loading state while processing', async ({ page }) => {
+      await page.route('**/auth/zalo/callback**', (route) =>
+        new Promise(() => {
+          // Never resolve
+        }),
+      );
+
+      await page.goto('/auth/callback/zalo?code=test-code');
+      await expect(page.locator('.animate-spin').first()).toBeVisible({ timeout: 5000 });
+    });
+
+    test('redirects to login with error on failure', async ({ page }) => {
+      await page.route('**/auth/zalo/callback**', (route) =>
+        route.fulfill({
+          status: 401,
+          contentType: 'application/json',
+          body: JSON.stringify({ message: 'OAuth failed' }),
+        }),
+      );
+
+      await page.goto('/auth/callback/zalo?code=bad-code');
+      await expect(page).toHaveURL(/\/login\?error=/, { timeout: 10000 });
+    });
+  });
+});