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

src/admin/components/ui/dialog.js

@@ -0,0 +1,86 @@
+import * as DialogPrimitive from '@radix-ui/react-dialog';
+import { cn } from '@/lib/utils';
+
+function Dialog({ ...props }) {
+    return <DialogPrimitive.Root data-slot="dialog" {...props} />;
+}
+
+function DialogTrigger({ ...props }) {
+    return <DialogPrimitive.Trigger data-slot="dialog-trigger" {...props} />;
+}
+
+function DialogPortal({ ...props }) {
+    return <DialogPrimitive.Portal data-slot="dialog-portal" {...props} />;
+}
+
+function DialogClose({ ...props }) {
+    return <DialogPrimitive.Close data-slot="dialog-close" {...props} />;
+}
+
+function DialogOverlay({ className, ...props }) {
+    return (
+        <DialogPrimitive.Overlay
+            data-slot="dialog-overlay"
+            className={cn(
+                "fixed inset-0 z-50 bg-black/80 data-[state=open]:animate-in data-[state=closed]:animate-out data-[state=closed]:fade-out-0 data-[state=open]:fade-in-0",
+                className
+            )}
+            {...props}
+        />
+    );
+}
+
+function DialogContent({ className, children, ...props }) {
+    return (
+        <DialogPortal>
+            <DialogOverlay />
+            <DialogPrimitive.Content
+                data-slot="dialog-content"
+                className={cn(
+                    "fixed left-[50%] top-[50%] z-50 grid w-full max-w-lg translate-x-[-50%] translate-y-[-50%] gap-4 border bg-background p-6 shadow-lg duration-200 data-[state=open]:animate-in data-[state=closed]:animate-out data-[state=closed]:fade-out-0 data-[state=open]:fade-in-0 data-[state=closed]:zoom-out-95 data-[state=open]:zoom-in-95 data-[state=closed]:slide-out-to-left-1/2 data-[state=closed]:slide-out-to-top-[48%] data-[state=open]:slide-in-from-left-1/2 data-[state=open]:slide-in-from-top-[48%] sm:rounded-lg",
+                    className
+                )}
+                {...props}
+            >
+                {children}
+            </DialogPrimitive.Content>
+        </DialogPortal>
+    );
+}
+
+function DialogHeader({ className, ...props }) {
+    return (
+        <div data-slot="dialog-header" className={cn("flex flex-col space-y-1.5 text-center sm:text-left", className)} {...props} />
+    );
+}
+
+function DialogFooter({ className, ...props }) {
+    return (
+        <div data-slot="dialog-footer" className={cn("flex flex-col-reverse sm:flex-row sm:justify-end sm:space-x-2", className)} {...props} />
+    );
+}
+
+function DialogTitle({ className, ...props }) {
+    return (
+        <DialogPrimitive.Title data-slot="dialog-title" className={cn("text-lg font-semibold leading-none tracking-tight", className)} {...props} />
+    );
+}
+
+function DialogDescription({ className, ...props }) {
+    return (
+        <DialogPrimitive.Description data-slot="dialog-description" className={cn("text-sm text-muted-foreground", className)} {...props} />
+    );
+}
+
+export {
+    Dialog,
+    DialogPortal,
+    DialogOverlay,
+    DialogClose,
+    DialogTrigger,
+    DialogContent,
+    DialogHeader,
+    DialogFooter,
+    DialogTitle,
+    DialogDescription,
+};