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/shop-admin/nuxt.config.ts

@@ -1,6 +1,9 @@
+import tailwindcss from "@tailwindcss/vite";
+
 export default defineNuxtConfig({
-  modules: ["@pinia/nuxt", "@nuxtjs/i18n"],
-  css: ["@vmall/shared/ui.css"],
+  modules: ["@pinia/nuxt", "@nuxtjs/i18n", "@vmall/ui/nuxt"],
+  css: ["@vmall/shared/theme.css"],
+  vite: { plugins: [tailwindcss()] },
   devtools: { enabled: false },
   devServer: { port: 3001 },
   runtimeConfig: {