Docs: Python example uses nonexistent `selection_func` in add_fan_out_edges

[Kimcheolhui]

semantic-kernel-docs/agent-framework/user-guide/workflows/core-concepts/edges.md

Lines 174 to 195 in 56dbe96

	```python
	from agent_framework import WorkflowBuilder
	builder = WorkflowBuilder()
	builder.set_start_executor(splitter_executor)
	builder.add_fan_out_edges(splitter_executor, [worker1, worker2, worker3])
	workflow = builder.build()
	# Send to specific targets based on partitioner function
	builder = WorkflowBuilder()
	builder.set_start_executor(splitter_executor)
	builder.add_fan_out_edges(
	splitter_executor,
	[worker1, worker2, worker3],
	selection_func=lambda message, target_ids: (
	[0] if message.priority == Priority.HIGH else
	[1, 2] if message.priority == Priority.NORMAL else
	list(range(target_count))
	)
	)
	workflow = builder.build()
	```

The Python example in the Edges guide shows add_fan_out_edges(..., selection_func=...), but this parameter does not exist in the actual Python SDK.

According to the Python API reference, add_fan_out_edges does not support selection_func. Selection logic in Python is handled by a different API (add_multi_selection_edge_group).

The documentation and the real Python API surface are inconsistent.

References

Edges guide (problematic example):
https://learn.microsoft.com/en-us/agent-framework/user-guide/workflows/core-concepts/edges?pivots=programming-language-python

Python API spec for add_fan_out_edges:
https://learn.microsoft.com/en-us/python/api/agent-framework-core/agent_framework.workflowbuilder?view=agent-framework-python-latest#agent-framework-workflowbuilder-add-fan-out-edges