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

tests/test_deepseek_infra.py

@@ -1,3 +1,4 @@
+from typing import Any
 import pytest
 import os
 import tomllib
@@ -11,7 +12,7 @@ sys.path.append(os.path.abspath(os.path.join(os.path.dirname(__file__), "..")))
 import ai_client
 import project_manager
 
-def test_credentials_error_mentions_deepseek(monkeypatch):
+def test_credentials_error_mentions_deepseek(monkeypatch: pytest.MonkeyPatch) -> None:
  """
     Verify that the error message shown when credentials.toml is missing
     includes deepseek instructions.
@@ -48,7 +49,7 @@ def test_deepseek_model_listing() -> None:
  assert "deepseek-chat" in models
  assert "deepseek-reasoner" in models
 
-def test_gui_provider_list_via_hooks(live_gui):
+def test_gui_provider_list_via_hooks(live_gui: Any) -> None:
  """
     Verify 'deepseek' is present in the GUI provider list using API hooks.
     """