refactor(tests): Add strict type hints to fifth batch of test files

tests/conftest.py

@@ -5,6 +5,7 @@ import requests
 import os
 import signal
 import sys
+from typing import Generator
 import os
 
 # Ensure project root is in path
@@ -14,14 +15,14 @@ from api_hook_client import ApiHookClient
 import ai_client
 
 @pytest.fixture(autouse=True)
-def reset_ai_client() -> None:
+def reset_ai_client() -> Generator[None, None, None]:
  """Reset ai_client global state between every test to prevent state pollution."""
  ai_client.reset_session()
  # Default to a safe model
  ai_client.set_provider("gemini", "gemini-2.5-flash-lite")
  yield
 
-def kill_process_tree(pid):
+def kill_process_tree(pid: int | None) -> None:
  """Robustly kills a process and all its children."""
  if pid is None:
   return
@@ -41,7 +42,7 @@ def kill_process_tree(pid):
   print(f"[Fixture] Error killing process tree {pid}: {e}")
 
 @pytest.fixture(scope="session")
-def live_gui() -> None:
+def live_gui() -> Generator[tuple[subprocess.Popen, str], None, None]:
  """
     Session-scoped fixture that starts gui_2.py with --enable-test-hooks.
     """