Add environment configuration and email settings

- Created a new .env.example file for environment variable configuration including Django settings, email configurations, and common SMTP provider examples.
- Updated .vscode/settings.json to include additional words for spell checking.
- Enhanced config/settings.py to load environment variables using python-dotenv, added data directory management, and configured email settings.
- Updated config/urls.py to include debug toolbar URLs conditionally based on testing.
- Added pytest configuration in conftest.py for Django testing.
- Created core application with custom User model, admin registration, and migrations.
- Implemented tests for User model and admin functionalities.
- Updated pyproject.toml to include new dependencies for debugging and environment management.
- Updated uv.lock to reflect new package versions and dependencies.

config/urls.py

@@ -2,6 +2,8 @@ from __future__ import annotations
 
 from typing import TYPE_CHECKING
 
+from debug_toolbar.toolbar import debug_toolbar_urls  # pyright: ignore[reportMissingTypeStubs]
+from django.conf import settings
 from django.contrib import admin
 from django.urls import path
 
@@ -11,3 +13,6 @@ if TYPE_CHECKING:
 urlpatterns: list[URLResolver] = [
     path(route="admin/", view=admin.site.urls),
 ]
+
+if not settings.TESTING:
+    urlpatterns = [*urlpatterns, *debug_toolbar_urls()]