feat(nodes): add background investigation node

Change-Id: I96e08e22fc7c52647edbf9be4f385a8fae9b449a

src/workflow.py

@@ -28,6 +28,7 @@ async def run_agent_workflow_async(
     debug: bool = False,
     max_plan_iterations: int = 1,
     max_step_num: int = 3,
+    enable_background_investigation: bool = True,
 ):
     """Run the agent workflow asynchronously with the given user input.
 
@@ -36,6 +37,7 @@ async def run_agent_workflow_async(
         debug: If True, enables debug level logging
         max_plan_iterations: Maximum number of plan iterations
         max_step_num: Maximum number of steps in a plan
+        enable_background_investigation: If True, performs web search before planning to enhance context
 
     Returns:
         The final state after the workflow completes
@@ -51,6 +53,7 @@ async def run_agent_workflow_async(
         # Runtime Variables
         "messages": [{"role": "user", "content": user_input}],
         "auto_accepted_plan": True,
+        "enable_background_investigation": enable_background_investigation,
     }
     config = {
         "configurable": {