fix(e2e): replace networkidle in messaging tests + auth-helpers

Same root cause as the BasePage fix (ca6e013): networkidle never
fires on pages with Supabase Realtime subscriptions. The /messages
page has active WebSocket channels that prevent the 500ms idle
window from closing.

Run 24221957976: 13/18 green (all gen shards), 5/18 red (all msg
shards). Every msg failure traced back to networkidle timeouts in
loginAndVerify() fallback or direct calls in test files.

Replaced 9 occurrences across 5 files:
  - auth-helpers.ts:90 — loginAndVerify() WebKit fallback (highest
    impact: used by every messaging test)
  - complete-user-workflow.spec.ts — 3 calls (lines 439, 491, 680)
  - group-chat-multiuser.spec.ts — 2 calls (lines 52, 176)
  - offline-queue.spec.ts — 2 calls (lines 364, 365)
  - friend-requests.spec.ts — 1 call (line 747)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: YourGitHubUsername

tests/e2e/messaging/complete-user-workflow.spec.ts

@@ -436,7 +436,7 @@ test.describe('Complete User Messaging Workflow (Feature 024)', () => {
           name: /pending received|received/i,
         });
         await receivedTab.click({ force: true });
-        await pageB.waitForLoadState('networkidle');
+        await pageB.waitForLoadState('domcontentloaded');
         requestVisible = await pageB
           .locator('[data-testid="connection-request"]')
           .isVisible({ timeout: 8000 })
@@ -488,7 +488,7 @@ test.describe('Complete User Messaging Workflow (Feature 024)', () => {
           'Step 7: connection-request not visible, reloading pageB...'
         );
         await pageB.reload();
-        await pageB.waitForLoadState('networkidle');
+        await pageB.waitForLoadState('domcontentloaded');
         await dismissCookieBanner(pageB);
         await dismissReAuthModal(pageB, USER_B.password, true);
 
@@ -677,7 +677,7 @@ test.describe('Conversations Page Loading (Feature 029)', () => {
     await page.goto('/messages?tab=chats');
     await dismissCookieBanner(page);
     await completeEncryptionSetup(page);
-    await page.waitForLoadState('networkidle');
+    await page.waitForLoadState('domcontentloaded');
     await dismissReAuthModal(page);
 
     // If error is shown, verify retry button exists

tests/e2e/messaging/friend-requests.spec.ts

@@ -744,7 +744,7 @@ test.describe('Accessibility', () => {
     await dismissCookieBanner(page);
     await completeEncryptionSetup(page);
     await dismissReAuthModal(page);
-    await page.waitForLoadState('networkidle');
+    await page.waitForLoadState('domcontentloaded');
 
     // Verify all tabs exist with correct roles and are clickable
     const sentTab = page.getByRole('tab', { name: /pending sent|sent/i });

tests/e2e/messaging/group-chat-multiuser.spec.ts

@@ -49,7 +49,7 @@ async function signInAndNavigateToMessages(page: Page) {
   await page.goto(BASE_URL + '/messages');
   await dismissCookieBanner(page);
   await completeEncryptionSetup(page);
-  await page.waitForLoadState('networkidle');
+  await page.waitForLoadState('domcontentloaded');
   await dismissReAuthModal(page);
 }
 
@@ -173,7 +173,7 @@ test.describe('Group Chat E2E', () => {
       // Wait for new-group page
       await page.waitForURL(/.*\/messages\/new-group/, { timeout: 10000 });
       await dismissCookieBanner(page);
-      await page.waitForLoadState('networkidle');
+      await page.waitForLoadState('domcontentloaded');
 
       // Enter group name
       const groupNameInput = page.locator('#group-name');

tests/e2e/messaging/offline-queue.spec.ts

@@ -361,8 +361,8 @@ test.describe('Offline Message Queue', () => {
       await completeEncryptionSetup(pageB, USER_B.password);
       await dismissReAuthModal(pageB, USER_B.password);
 
-      await pageA.waitForLoadState('networkidle');
-      await pageB.waitForLoadState('networkidle');
+      await pageA.waitForLoadState('domcontentloaded');
+      await pageB.waitForLoadState('domcontentloaded');
 
       const threadLocator =
         '[data-testid*="message"], textarea[aria-label="Message input"]';

tests/e2e/utils/auth-helpers.ts

@@ -87,7 +87,7 @@ export async function loginAndVerify(
       });
       break; // Success — URL changed
     } catch {
-      await page.waitForLoadState('networkidle');
+      await page.waitForLoadState('domcontentloaded');
       if (!page.url().includes('/sign-in')) {
         break; // WebKit fallback — URL did change
       }