Fix networkidle timeouts and Firefox cookie domain normalization

- Replace networkidle with domcontentloaded + 5s race in goto, click,
  and session_restore — SPAs with persistent connections (LinkedIn,
  Gmail) never reach networkidle
- Normalize .www. cookie domains in Firefox importer — Playwright
  silently drops cookies with .www.example.com domains

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

src/mcp.ts

@@ -665,7 +665,10 @@ server.tool(
 
     // Navigate to saved URL
     if (data.url) {
-      await page.goto(data.url, { waitUntil: 'networkidle' });
+      await page.goto(data.url, { waitUntil: 'domcontentloaded' });
+      await Promise.race([page.waitForLoadState('networkidle'), page.waitForTimeout(5000)]).catch(
+        () => {}
+      );
     }
 
     // Restore storage (runs in browser context)