fix: use dot notation for ActionSearch object to prevent TypeError

This fix addresses a TypeError: 'ActionSearch' object is not subscriptable caused by treating an ActionSearch object like a dictionary. The code now correctly uses dot notation (search.action.query instead of search.action["query"]).

Author: aajinn

examples/deep_research_api/introduction_to_deep_research_api.ipynb

@@ -252,7 +252,7 @@
       "source": [
         "# Find the first web search step\n",
         "search = next(item for item in response.output if item.type == \"web_search_call\")\n",
-        "print(\"Query:\", search.action[\"query\"])\n",
+        "print(\"Query:\", search.action.query)\n",
         "print(\"Status:\", search.status)"
       ]
     },