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>

simulation/sim_base.py

@@ -9,7 +9,7 @@ from simulation.workflow_sim import WorkflowSimulator
 sys.path.append(os.path.abspath(os.path.join(os.path.dirname(__file__), "..")))
 
 class BaseSimulation:
- def __init__(self, client: ApiHookClient = None):
+ def __init__(self, client: ApiHookClient = None) -> None:
   if client is None:
    self.client = ApiHookClient()
   else:
@@ -36,7 +36,7 @@ class BaseSimulation:
   self.client.set_value("current_model", "gemini-2.5-flash-lite")
   time.sleep(0.2)
 
- def teardown(self):
+ def teardown(self) -> None:
   if self.project_path and os.path.exists(self.project_path):
   # We keep it for debugging if it failed, but usually we'd clean up
   # os.remove(self.project_path)