feat: Implement user authentication and database migration system

- Refactored AuthService to use UserRepository for user authentication.
- Added .env file for environment configuration.
- Created migration system with Migrator and ConnectionFactory classes.
- Added database migration files for creating users table.
- Implemented settings controller for managing database migrations.
- Developed user repository for user data handling.
- Created users controller for user management interface.
- Added frontend standards and migration documentation.
- Introduced reusable UI components and jQuery alerts module.

.env.example

@@ -4,5 +4,10 @@ APP_DEBUG=true
 APP_URL=http://localhost:8000
 SESSION_NAME=orderpro_session
 
-ADMIN_EMAIL=admin@orderpro.local
-ADMIN_PASSWORD_HASH=$2y$10$1eRQmrhEUWgKRZpG08dKOenG4eZrvLQnLdCUfKHrZ/5dzLvxpmRYC
+DB_CONNECTION=mysql
+DB_HOST=127.0.0.1
+DB_PORT=3306
+DB_DATABASE=orderpro
+DB_USERNAME=root
+DB_PASSWORD=
+DB_CHARSET=utf8mb4