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/dialog/dialog.tsx

@@ -2,7 +2,7 @@
 
 import * as DialogPrimitive from '@radix-ui/react-dialog';
 import * as React from 'react';
-import { LuX } from 'react-icons/lu';
+import { X } from 'lucide-react';
 import { cn } from '@imphnen-frontend-service/utils';
 
 function Dialog({
@@ -70,7 +70,7 @@ function DialogContent({
             data-slot="dialog-close"
             className="ring-offset-background focus:ring-ring data-[state=open]:bg-accent data-[state=open]:text-muted-foreground absolute top-4 right-4 rounded-xs opacity-70 transition-opacity hover:opacity-100 focus:ring-2 focus:ring-offset-2 focus:outline-hidden disabled:pointer-events-none [&_svg]:pointer-events-none [&_svg]:shrink-0 [&_svg:not([class*='size-'])]:size-4"
           >
-            <LuX />
+            <X />
             <span className="sr-only">Close</span>
           </DialogPrimitive.Close>
         )}