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_cli_tool_bridge_mapping.py

@@ -12,7 +12,7 @@ sys.path.append(os.path.abspath(os.path.join(os.path.dirname(__file__), "..")))
 from scripts.cli_tool_bridge import main
 
 class TestCliToolBridgeMapping(unittest.TestCase):
- def setUp(self):
+ def setUp(self) -> None:
   os.environ['GEMINI_CLI_HOOK_CONTEXT'] = 'manual_slop'
 
  @patch('sys.stdin', new_callable=io.StringIO)