feat(backoffice): redesign backoffice UI dengan shadcn/ui

Menyeluruh merancang ulang apps/backoffice memakai pola shadcn/ui sambil
mempertahankan seluruh palette warna existing (primary/neutral/success/
info/warning/danger) dan typography Bai Jamjuree.

UI library (libs/ui):
- Atoms existing (Button, Input, Label, Textarea, Card, Dialog, Drawer,
  Form, Select, Toggle) dirombak ke pola shadcn, API dipertahankan agar
  sibling apps (gacha, dimentorin, hackathon, qrcampaign) tidak break
- Select atom beralih dari native ke Radix Select + NativeSelect fallback
- 18 atom baru: Badge, Avatar, Separator, Skeleton, Tabs, Tooltip,
  DropdownMenu, Popover, AlertDialog, Checkbox, RadioGroup, Switch,
  ScrollArea, Sheet, Sidebar, Breadcrumb, Table, + use-mobile hook
- DataTable, Filter, BackofficeWrapper, Pagination, Modal (alias Dialog)
  direstyle dengan token baru
- CSS variable layer shadcn ditambahkan (--color-primary, --color-sidebar-*,
  dll) dipetakan ke palette existing; tw-animate-css di-import untuk
  transisi

Backoffice shell:
- Sidebar bersarang SidebarProvider + SidebarInset, built-in mobile Sheet,
  user DropdownMenu (Avatar + logout), ikon lucide-react

Pages redesign (19 list/dashboard/settings):
- accounts, cms-events, cms-testimonials, dashboard, dashboard-dimentorin
  (dengan recharts di Card), feedback-review-dimentorin, gacha-roll,
  hackathon-dashboard, hackathon-submissions, hackathon-teams,
  hackathon-users, permissions, prizes, roadmap-dimentorin, roles,
  session-dimentorin, settings-dimentorin (Tabs), transactions,
  users-dimentorin (Tabs mentor/mentee)
- Pola unified: BackofficeWrapper > Card (CardHeader toolbar + CardContent
  DataTable) + AlertDialog untuk delete confirm
- Form accounts_/$id diredesign; form pages lain tetap pakai
  ControlledInputField yang sekarang berbasis shadcn Input

Dependencies:
- +20 radix-ui primitives, lucide-react, cmdk, input-otp
- Select native patched di dimentorin (profile-sidebar, schedule step)
  untuk tetap kompatibel via NativeSelect alias

Verifikasi:
- nx build backoffice: sukses (2.33s, 4801 modules)
- nx build dimentorin/gacha/hackathon/qrcampaign: semua sukses (zero
  regresi dari rewrite libs/ui)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

libs/ui/src/atoms/checkbox/checkbox.tsx

@@ -0,0 +1,39 @@
+'use client';
+
+import * as React from 'react';
+import * as CheckboxPrimitive from '@radix-ui/react-checkbox';
+import { Check, Minus } from 'lucide-react';
+import { cn } from '@imphnen-frontend-service/utils';
+
+function Checkbox({
+  className,
+  ...props
+}: React.ComponentProps<typeof CheckboxPrimitive.Root>) {
+  return (
+    <CheckboxPrimitive.Root
+      data-slot="checkbox"
+      className={cn(
+        'peer size-4 shrink-0 rounded-sm border border-neutral-300 bg-background shadow-sm',
+        'focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring focus-visible:ring-offset-2',
+        'disabled:cursor-not-allowed disabled:opacity-50',
+        'data-[state=checked]:bg-primary-500 data-[state=checked]:text-white data-[state=checked]:border-primary-500',
+        'data-[state=indeterminate]:bg-primary-500 data-[state=indeterminate]:text-white data-[state=indeterminate]:border-primary-500',
+        className
+      )}
+      {...props}
+    >
+      <CheckboxPrimitive.Indicator
+        data-slot="checkbox-indicator"
+        className="flex items-center justify-center text-current"
+      >
+        {props.checked === 'indeterminate' ? (
+          <Minus className="size-3.5" />
+        ) : (
+          <Check className="size-3.5" />
+        )}
+      </CheckboxPrimitive.Indicator>
+    </CheckboxPrimitive.Root>
+  );
+}
+
+export { Checkbox };