docs: README updates in subfolders

feat: sync integration updates across app and ML pipeline

Merge prepare_dataset.py from feature/ui-fix

evaluation: channel ablation script + feature importance LOPO

Put all the models together (expect UI)

remove old duplicate folders

reorg folders, add MLP demo

feat: data collection script, explorer notebook, sample sessions

chore: add template layout and stage 1 face mesh demo

set up template with folder structure and training script