Reachy Mini goes fully local

Reachy Mini users can now operate their robots entirely locally without relying on external servers by deploying a local speech-to-speech backend. This setup includes a cascade approach using components like Silero VAD for voice activity detection, Parakeet-TDT for speech-to-text, llama.cpp for local language model processing, and Qwen3-TTS for text-to-speech. This local deployment ensures privacy, eliminates API costs, and allows users full control over the speech pipeline, enabling them to swap components as new models become available. The system's flexibility is enhanced by the ability to use various models for language processing, either running locally or via different external inference engines, which communicate through a standardized API protocol.