full page: Part1 overfit (v3/causal/contact) + Part2 cross-arch causal-vs-noncausal (V+T, vision-only, tactile-only), 120 synced videos

sync player: shared draggable scrubber, tactile clips slaved to view clock

complete: train+val for v3/causal/contact (24 samples, full overfit tables)

overfit + rollout quality page (preview: v3 both splits, causal/contact val)

initial commit