feat(ui): adopt Tailwind v4 design system and archive change

- Add tailwindcss v4 + @tailwindcss/vite to mall, shop-admin, admin
- Add @vmall/shared/theme.css tokens with html[data-accent] presets
- Add @vmall/ui kit (VBtn/VBadge/VField/VInput/VCard/VPanel/VTable/VPage,
  VAccentSwatch, useAccent) as a Nuxt module
- Convert all three apps to kit + utilities; delete ui.css/mall.css and
  every <style scoped>; consoles get accent presets, mall locked to red
- Fix VCard boolean prop default (padding) and PDP/store stale
  useAsyncData keys on param navigation
- Archive adopt-tailwind-design-system; new frontend-ui capability spec

apps/mall/components/ui/StepBar.vue

@@ -3,48 +3,18 @@ defineProps<{ steps: string[]; active: number }>();
 </script>
 
 <template>
-  <ol class="steps">
-    <li v-for="(s, i) in steps" :key="s" :class="{ done: i < active, on: i === active }">
-      <span class="n">{{ i + 1 }}</span>
-      <span class="label">{{ s }}</span>
+  <ol class="mb-5 flex list-none border border-border bg-bg py-3.5">
+    <li
+      v-for="(s, i) in steps"
+      :key="s"
+      class="flex-1 text-center text-[13px] text-muted/70"
+      :class="i === active ? 'font-semibold text-primary' : ''"
+    >
+      <span
+        class="mr-2 inline-block h-[22px] w-[22px] rounded-full text-center text-[12px] leading-[22px] text-white"
+        :class="i < active ? 'bg-success' : i === active ? 'bg-primary' : 'bg-[#ddd]'"
+      >{{ i + 1 }}</span>
+      <span>{{ s }}</span>
     </li>
   </ol>
 </template>
-
-<style scoped>
-.steps {
-  display: flex;
-  list-style: none;
-  margin: 0 0 20px;
-  padding: 14px 0;
-  background: #fafafa;
-  border: 1px solid var(--mall-line);
-}
-li {
-  flex: 1;
-  text-align: center;
-  color: var(--mall-faint);
-  font-size: 13px;
-}
-.n {
-  display: inline-block;
-  width: 22px;
-  height: 22px;
-  line-height: 22px;
-  border-radius: 50%;
-  background: #ddd;
-  color: #fff;
-  margin-right: 8px;
-  font-size: 12px;
-}
-li.on {
-  color: var(--mall-red);
-  font-weight: 600;
-}
-li.on .n {
-  background: var(--mall-red);
-}
-li.done .n {
-  background: var(--mall-green);
-}
-</style>