fix(sae,compare): unstick train UI and restore GROUP_* badges

feat(sae): Top-K Clean/Denoise with sparse encode I/O

feat(compare): GROUP_* parse, contiguous sequence, floating group badges

feat(ui): English-only product copy and EN Compare vocab

feat(compare): add cosine-vs-anchor list with 3D reorder tween

feat(ui): add front-facing Analysis view with floating Glassmorphic thread labels and 5-thread vertical stack