feat: add shadcn/ui + Tailwind CSS v4 + Huge Icons foundation

- Install tailwindcss, @tailwindcss/postcss, clsx, tailwind-merge, class-variance-authority
- Install @hugeicons/react for icons
- Install Radix UI primitives (switch, tabs, label, separator, select, dialog, checkbox, dropdown-menu, popover)
- Install sonner for toast notifications
- Create postcss.config.js with Tailwind v4 PostCSS plugin
- Create jsconfig.json with @ path alias for src/admin
- Create components.json for shadcn configuration
- Update webpack.config.js with @ resolve alias
- Create globals.css with Tailwind v4 CSS-first config + shadcn CSS variables
- Create cn() utility in lib/utils.js
- Create 17 shadcn UI components (button, input, label, checkbox, switch, tabs, alert, separator, badge, textarea, dialog, sonner, table, skeleton, select, dropdown-menu, popover)
- Create async confirm() utility replacing SweetAlert2
- Create toast utility wrapping sonner

package.json

@@ -15,14 +15,31 @@
     "packages-update": "wp-scripts packages-update"
   },
   "devDependencies": {
-    "@wordpress/scripts": "^27.0.0"
+    "@wordpress/scripts": "^27.0.0",
+    "tw-animate-css": "^1.4.0"
   },
   "dependencies": {
+    "@hugeicons/react": "^1.1.6",
+    "@radix-ui/react-checkbox": "^1.3.3",
+    "@radix-ui/react-dialog": "^1.1.15",
+    "@radix-ui/react-dropdown-menu": "^2.1.16",
+    "@radix-ui/react-label": "^2.1.8",
+    "@radix-ui/react-popover": "^1.1.15",
+    "@radix-ui/react-select": "^2.2.6",
+    "@radix-ui/react-separator": "^1.1.8",
+    "@radix-ui/react-switch": "^1.2.6",
+    "@radix-ui/react-tabs": "^1.1.13",
+    "@tailwindcss/postcss": "^4.2.2",
     "@wordpress/api-fetch": "^6.0.0",
     "@wordpress/components": "^25.0.0",
     "@wordpress/data": "^9.0.0",
     "@wordpress/element": "^5.0.0",
     "@wordpress/i18n": "^4.0.0",
-    "@wordpress/icons": "^9.0.0"
+    "@wordpress/icons": "^9.0.0",
+    "class-variance-authority": "^0.7.1",
+    "clsx": "^2.1.1",
+    "sonner": "^2.0.7",
+    "tailwind-merge": "^3.5.0",
+    "tailwindcss": "^4.2.2"
   }
 }