fix(showcase): render Badge/Card/Loader/Stack demos correctly + bump @civitai/* 0.2.0

[ZacxDev]

What

Four visual bugs a maintainer reported on the live design-system showcase
(developer.civitai.com/apps/showcase) — all invisible to the existing E2E,
which passed 21/21 while these shipped because it asserted only
background / radius / font, never padding / border / rendered-size. Also
bumps the showcase's @civitai/* pins 0.1.2 → 0.2.0 and adds demos for the
components 0.2.0 introduces (Select / Checkbox / Radio).

Root cause per bug (inspected in a headless build, not guessed)

Shared root cause for 3 of the 4 — a stripped border. Tailwind Preflight,
pulled in transitively by vitepress-openapi, ships an UNLAYERED
*,::before,::after { border-width:0; border-style:solid; border-color:#e4e4e7 }.
Every @civitai/components rule lives in @layer civitai.components, and
unlayered CSS beats a layer — so that reset zeroes every component border
inside .cds-preview. The pre-existing all: revert-layer preview fix only
covered [data-civitai-ui='button'] + [data-civitai-ui-control], leaving the
presentational components stripped.

1. Badge — no padding + outline has no outline. Two causes: (a) the demo
   badges omitted data-variant / data-size, and the published CSS applies
   padding + fill only for an explicit variant/size; (b) the outline
   border was zeroed by the Preflight reset. Fix: give every demo badge an
   explicit data-variant + data-size; revert-layer restores the outline
   border. outline is a real Badge variant (not a package gap).
2. Card data-with-border shows no border. The 1px border was zeroed by
   the Preflight reset (card padding survived — border-specific). Fixed by the
   broadened revert-layer; the 0.2.0 bump additionally gives borderless cards a
   subtle default hairline.
3. Stack/Group demos too basic. Pure demo weakness (badges/buttons as filler
   didn't show direction or gap). Redesigned — see below.
4. Loader demo empty. The spinner is a CSS border ring; the Preflight
   reset zeroed its border-width, so it rendered as a 0-width invisible circle
   (the box had size, just no ring). Fixed by the broadened revert-layer.

None of the four is a @civitai/components code bug — all are showcase-side
(preview scoping + demo markup). One package doc/impl mismatch flagged, not
fixed here: MARKUP.md documents data-variant: filled (default) and
data-size: md (default) for Badge, but the published CSS implements neither
default (a bare <span data-civitai-ui="badge"> — including MARKUP's own minimal
example — renders fully unstyled). Worth a follow-up package fix so the
documented defaults actually apply.

Fix

• .vitepress/theme/design-system.css — broaden the preview
  all: revert-layer from button+-control to every [data-civitai-ui]
  (still .cds-preview-scoped; the VitePress chrome has no [data-civitai-ui]
  and is untouched — asserted by the existing chrome-non-regression checks).
• apps/showcase.md — Badge rows carry explicit variant+size; Card copy
  reflects 0.2.0's default hairline vs explicit border; Stack/Group redesigned
  with numbered filled chips laid out vertically (Stack) vs horizontally (Group)
  with clear labels + visible gap; added Select / Checkbox / Radio+RadioGroup
  demos; pin reference → 0.2.0.
• package.json / lockfile — @civitai/{components,components-react,theme}
0.1.2 → 0.2.0.

New E2E coverage (closes the gap)

scripts/test-showcase-e2e.mjs gains 8 render-integrity assertions (light
and dark) that fail on the old build and pass on this one:

• Badge has non-zero horizontal padding; outline variant has a >=1px
  primary-colored border (not the reset #e4e4e7).
• Card data-with-border has a non-zero, token-colored border (light + dark).
• Loader preview renders a non-empty box and a non-zero ring border.
• Stack/Group demo contains >=6 visible, non-transparent child chips.

Verbatim result (all green):

Showcase E2E: 29 checks · 29 passed · 0 failed   (was 21; snippet accuracy now 12 demos)
App Blocks snippets: 21 found · 21 passed · 0 skipped · 0 failed
TokenGallery drift: 27 exported · 27 rendered — ✓ matches @civitai/theme exactly

Verified

Reproduced all four bugs on the pre-fix build and confirmed each fixed on the
post-fix build via headless Chromium, light + dark: Badge → padded pills with
a visible outline + solid intent colors; Card → both cards bordered; Loader → four
visible spinner rings (was blank); Stack/Group → obvious vertical-vs-horizontal
numbered chips.

🤖 Generated with Claude Code