- docs/DESIGN.md: the written source of truth for the UI. Decided chapters
(principles, device adaptation, action placement, text stays selectable,
interaction rules, copy, anti-patterns, decision log); controls and
surfaces are marked Pending until the owner picks from the lab.
- /design-lab (dev only): renders each open decision's variants with the
app's real CSS, themes and font scale. Batch A = six control decisions.
- devOnlyGuard: a production build fails if anything under src/design-lab
reaches the bundle (seen red with an unguarded import).
- Size contract: tablet portrait + landscape and up, replacing the
1024x768 floor with its never-built "too small" message.