fix(notebooks): correct rustup invocation flags and StateGraph heading

- Remove -s and -- from subprocess.run(["/bin/sh", _rustup_path, ...]):
  -s reads script from stdin, which is wrong when passing a file path.
  Correct form is ["/bin/sh", path, "-y", "-q"].
  Applies to notebooks 01, 02, and 03.
- Rename "LangGraph StatefulGraph" heading to "LangGraph StateGraph"
  in notebook 03: langgraph exports StateGraph, not StatefulGraph.

Author: polaz

demo/notebooks/01_llama_index_property_graph.ipynb

@@ -69,7 +69,7 @@
     "            _f.write(_r.read())\n",
     "        _rustup_path = _f.name\n",
     "    try:\n",
-    "        subprocess.run([\"/bin/sh\", _rustup_path, \"-s\", \"--\", \"-y\", \"-q\"], check=True, timeout=300)\n",
+    "        subprocess.run([\"/bin/sh\", _rustup_path, \"-y\", \"-q\"], check=True, timeout=300)\n",
     "    finally:\n",
     "        os.unlink(_rustup_path)\n",
     "    # Add cargo to PATH so maturin/pip can find it.\n",

demo/notebooks/02_langchain_graph_chain.ipynb

@@ -66,7 +66,7 @@
     "            _f.write(_r.read())\n",
     "        _rustup_path = _f.name\n",
     "    try:\n",
-    "        subprocess.run([\"/bin/sh\", _rustup_path, \"-s\", \"--\", \"-y\", \"-q\"], check=True, timeout=300)\n",
+    "        subprocess.run([\"/bin/sh\", _rustup_path, \"-y\", \"-q\"], check=True, timeout=300)\n",
     "    finally:\n",
     "        os.unlink(_rustup_path)\n",
     "    # Add cargo to PATH so maturin/pip can find it.\n",

demo/notebooks/03_langgraph_agent.ipynb

@@ -66,7 +66,7 @@
     "            _f.write(_r.read())\n",
     "        _rustup_path = _f.name\n",
     "    try:\n",
-    "        subprocess.run([\"/bin/sh\", _rustup_path, \"-s\", \"--\", \"-y\", \"-q\"], check=True, timeout=300)\n",
+    "        subprocess.run([\"/bin/sh\", _rustup_path, \"-y\", \"-q\"], check=True, timeout=300)\n",
     "    finally:\n",
     "        os.unlink(_rustup_path)\n",
     "    # Add cargo to PATH so maturin/pip can find it.\n",
@@ -347,7 +347,7 @@
    "id": "d4e5f6a7-0003-0000-0000-000000000010",
    "metadata": {},
    "source": [
-    "## 3. LangGraph StatefulGraph — manual workflow\n",
+    "## 3. LangGraph StateGraph — manual workflow\n",
     "\n",
     "Shows how to wire CoordiNode tool calls into a LangGraph state machine without an LLM."
    ]