Update project configuration and dependencies

- Added `.vscode` to `.gitignore` to exclude Visual Studio Code settings.
- Updated `pyproject.toml` to include `ruff` for linting and configured its settings.
- Modified `uv.lock` to include `ruff` in both optional and development dependencies.
- Refactored type hints in several files to use `str | None` for optional parameters.
- Cleaned up unused imports and whitespace in various modules for improved code clarity.

oxi/interfaces/models/__init__.py

@@ -3,5 +3,5 @@ import pkgutil
 
 package = __package__
 
-for loader, module_name, is_pkg in pkgutil.iter_modules(__path__):
+for _, module_name, _ in pkgutil.iter_modules(__path__):
     importlib.import_module(f"{package}.{module_name}")