fix(ci): skip graph node tests when agentic extras not installed

test_graph_nodes.py imports NodeFactory which requires langchain_core.
Add pytest.importorskip to gracefully skip when [agentic] not installed.

Author: morganrcu

tests/test_graph_nodes.py

@@ -2,6 +2,10 @@
 import os
 from unittest.mock import MagicMock, patch
 
+import pytest
+
+pytest.importorskip("langchain_core", reason="Requires venturalitica[agentic]")
+
 from venturalitica.assurance.graph.nodes import NodeFactory
 from venturalitica.assurance.graph.state import ComplianceState