refactor(types): auto -> None sweep across entire codebase

Applied 236 return type annotations to functions with no return values
across 100+ files (core modules, tests, scripts, simulations).
Added Phase 4 to python_style_refactor track for remaining 597 items
(untyped params, vars, and functions with return values).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

tests/test_api_hook_client.py

@@ -56,7 +56,7 @@ def test_get_performance_success(live_gui):
  response = client.get_performance()
  assert "performance" in response
 
-def test_unsupported_method_error():
+def test_unsupported_method_error() -> None:
  """
     Test that calling an unsupported HTTP method raises a ValueError.
     """
@@ -64,7 +64,7 @@ def test_unsupported_method_error():
  with pytest.raises(ValueError, match="Unsupported HTTP method"):
   client._make_request('PUT', '/some_endpoint', data={'key': 'value'})
 
-def test_get_text_value():
+def test_get_text_value() -> None:
  """
     Test retrieval of string representation using get_text_value.
     """
@@ -74,7 +74,7 @@ def test_get_text_value():
  with patch.object(client, 'get_value', return_value=None):
   assert client.get_text_value("dummy_tag") is None
 
-def test_get_node_status():
+def test_get_node_status() -> None:
  """
     Test retrieval of DAG node status using get_node_status.
     """