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_conductor_engine.py

@@ -6,7 +6,7 @@ import ai_client
 # These tests define the expected interface for multi_agent_conductor.py
 # which will be implemented in the next phase of TDD.
 
-def test_conductor_engine_initialization():
+def test_conductor_engine_initialization() -> None:
  """
     Test that ConductorEngine can be initialized with a Track.
     """