Introduce multiple new modules including unified_engine_api, unified_engine_audio, unified_engine_bridge, unified_engine_builder, unified_engine_components, unified_engine_delegates, and unified_engine_runtime. These additions provide a comprehensive framework for managing TTS requests, audio packing, and engine state management, significantly improving the architecture and maintainability of the TTS system. The new structure supports asynchronous operations and enhances overall performance through better request handling and processing capabilities.
