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.

core/admin.py

@@ -0,0 +1,9 @@
+from __future__ import annotations
+
+from django.contrib import admin
+from django.contrib.auth.admin import UserAdmin
+
+from core.models import User
+
+# Register your custom User model with the admin
+admin.site.register(User, UserAdmin)