Update app.py

app.py

@@ -196,7 +196,7 @@ async def launch(request: BrowserLaunchRequest):
         
         # Store session
         browser_instances[session_id] = {
-            "playwright_browser": browser,
+            "playwright_browser": browser_pool,
             "playwright_context": ctx,
             "playwright_page": page,
             "created_at": time.time(),