Update README to clarify VAD mode behavior: provisional caption only after Silero detects speech, Parakeet idle during silence. Document new --vad-threshold option to control Silero speech confidence. Add troubleshooting tip for music/noise false detections.
Move the executable entry point to `src/cmd/captioneer` and split audio, capture, config, caption, and model logic into separate packages under `src/`. Update README with new build/run commands and a package-overview section.