Fix get_or_create_working_memory issue in 03_memory_integration

For new sessions, don't call get_or_create_working_memory as it fails
when the session doesn't exist. Instead, just start with empty working
memory and create it with put_working_memory.

Author: abrookins

python-recipes/context-engineering/notebooks/section-3-memory/03_memory_integration.ipynb

@@ -161,12 +161,9 @@
         "\n",
         "# Step 1: Load working memory (empty for first turn)\n",
         "print(\"\\n1. Loading working memory...\")\n",
-        "_, working_memory = await memory_client.get_or_create_working_memory(\n",
-        "    session_id=session_id_1,\n",
-        "    user_id=\"demo_user\",\n",
-        "    model_name=\"gpt-4o\"\n",
-        ")\n",
-        "print(f\"   Messages in working memory: {len(working_memory.messages) if working_memory else 0}\")\n",
+        "# For first turn, working memory is empty\n",
+        "working_memory = None\n",
+        "print(f\"   Messages in working memory: 0 (new session)\")\n",
         "\n",
         "# Step 2: Search long-term memory (empty for first interaction)\n",
         "print(\"\\n2. Searching long-term memory...\")\n",
@@ -366,12 +363,9 @@
         "\n",
         "# Step 1: Load working memory (empty - new session)\n",
         "print(\"\\n1. Loading working memory...\")\n",
-        "_, working_memory = await memory_client.get_or_create_working_memory(\n",
-        "    session_id=session_id_2,\n",
-        "    user_id=\"demo_user\",\n",
-        "    model_name=\"gpt-4o\"\n",
-        ")\n",
-        "print(f\"   Messages in working memory: {len(working_memory.messages) if working_memory else 0}\")\n",
+        "# For new session, working memory is empty\n",
+        "working_memory = None\n",
+        "print(f\"   Messages in working memory: 0\")\n",
         "print(\"   (Empty - this is a new session)\")\n",
         "\n",
         "# Step 2: Search long-term memory (has data from Session 1)\n",