Plan step 38: swatches move from Tailwind's bg-* role utilities to
data-md-showcase-swatch spans whose fill is the caller's own inline
style="background: var(--md-sys-color-{role})" (a swatch's colour
depends on the role it shows, so that one declaration cannot be a
class), sized and edged in showcase.css; the two grids and every
per-theme panel move onto <x-grid>, <x-surface> and <x-stack>; text
onto the md-type-*/md-ink-* classes. The legacy "Ink and lines" group
(bg-body, bg-meta, bg-quiet, bg-structure, bg-chrome, bg-divider) is
dropped — those Tailwind ink/line names end with Phase F and their
roles already show under Surface.
ThemeTest and ColourProfilesTest read the swatch's computed colour
through the new data-md-showcase-swatch="primary" hook instead of the
retired .bg-primary class.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Qwx5USif3wFFmxtHg5U1g9
