DESIGN.md: B1-B9 decided (compact density, the four-scheme set with the
accent-vs-status rule, state layers, the sticky band, surface per role, the
watch page, the slim NavRail with optional labels, loading by shape, the
fade edges) with their decision-log rows. The lab keeps the chosen A and B
renderings as reference on shared tokens (labTokens.ts) and adds batch C:
the action-placement classification for review, side panels on touch and
below 768, the Plex player on touch, and the dialog conventions.