Implement SQLite support using the pure Go `modernc.org/sqlite` driver and update the migration system to handle driver-specific schemas. Users can now choose between MySQL and SQLite by setting the `DB_DRIVER` environment variable.
Add a comprehensive guide for developers transitioning from Node/PHP and implement a new middleware to handle IP-based rate limiting with temporary banning functionality. Also refactors configuration loading to use a singleton pattern for better resource management.
