- Add WHISPER_MODEL_SIZE and WHISPER_MIN_FREE_SPACE_BYTES config options
- voice.py now preloads/downloads the Whisper model at bot startup
- Detailed logging for model presence, disk space, download progress and readiness
- If model is already present locally, preload is skipped
- If disk space is insufficient, bot fails fast with a clear error
- main.py calls preload_model() after proxy setup and before polling
- Document voice recognition model download behavior in README