Refactor test utilities and enhance ASGI settings

- Cleaned up and standardized assertions in ApiTestMixin for API response validation.
- Updated ASGI settings to use os.environ for setting the DJANGO_SETTINGS_MODULE.
- Removed unused imports and improved formatting in settings.py.
- Refactored URL patterns in urls.py for better readability and organization.
- Enhanced view functions in views.py for consistency and clarity.
- Added .flake8 configuration for linting and style enforcement.
- Introduced type stubs for django-environ to improve type checking with Pylance.

pyproject.toml

@@ -53,3 +53,19 @@ dependencies = [
     "django-extensions>=4.1",
     "werkzeug>=3.1.3",
 ]
+
+[dependency-groups]
+dev = [
+    "autoflake>=2.3.1",
+    "autopep8>=2.3.2",
+    "black>=25.1.0",
+    "django-stubs>=5.2.2",
+    "rope>=1.14.0",
+]
+
+[tool.pyright]
+stubPath = "stubs"
+typeCheckingMode = "basic"
+
+[tool.pylance]
+stubPath = "stubs"