🧪 test(workspaces): update temp_cache_dir fixture to use monkeypatch

@pytest.fixture

def temp_cache_dir(tmp_path: Path) -> Path:

def temp_cache_dir(tmp_path: Path, monkeypatch: pytest.MonkeyPatch) -> Path:

    """Create a temporary cache directory and register it."""

    # Reset CacheManager singleton to allow re-registration in tests

    CacheManager._instance = None

    cache_dir = tmp_path / ".3gpp-crawler"

    cache_dir.mkdir()

    monkeypatch.setenv("TDC_CACHE_DIR", str(cache_dir))

    # Reset CacheManager singleton to allow re-registration in tests

    CacheManager._instance = None

    CacheManager(cache_dir).register()

    return cache_dir