feat: migrate all 5 Vite apps from react-router to TanStack Router

Migrated backoffice, hackathon, dimentorin, gacha, qrcampaign, and
infra from custom react-router file-based routing to TanStack Router
file-based routing following the tanstack-frontend-best-practice
convention.

Key changes per app:
- New routes/ directory with __root.tsx, _public.tsx, _authenticated.tsx
- Auth guards via beforeLoad (replaces old middleware.ts)
- createFileRoute pattern for all page components
- TanStackRouterVite plugin in vite.config for auto route generation
- _components/_hooks folders colocated with routes (ignored by router)
- routeTree.gen.ts auto-generated on dev/build

Convention:
- _public/* routes redirect to dashboard if authenticated
- _authenticated/* routes redirect to /auth/login if not authenticated
- $param for dynamic segments (was [param] in old convention)
- _layout suffix for pathless layout routes

Removed:
- Old src/app/ directories from all apps
- Old src/middleware.ts files
- Custom convertPagesToRoute utility (no longer needed)
- react-router dependency usage (kept in package.json for shared libs)

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

apps/qrcampaign/src/routes/_authenticated.tsx

@@ -0,0 +1,46 @@
+import { createFileRoute, Outlet, redirect } from '@tanstack/react-router'
+import { useAuthStore } from '../app/features/auth/store/auth.store'
+import { Sidebar } from '../components/Sidebar'
+import { MenuOutlined } from '@ant-design/icons'
+import { useState } from 'react'
+
+export const Route = createFileRoute('/_authenticated')({
+  beforeLoad: () => {
+    const { isAuthenticated } = useAuthStore.getState()
+    if (!isAuthenticated) {
+      throw redirect({ to: '/auth/login' })
+    }
+  },
+  component: AuthenticatedLayout,
+})
+
+function AuthenticatedLayout() {
+  const [mobileSidebarOpen, setMobileSidebarOpen] = useState(false)
+
+  return (
+    <div className="flex min-h-screen bg-gray-50">
+      <Sidebar
+        isOpen={mobileSidebarOpen}
+        onClose={() => setMobileSidebarOpen(false)}
+      />
+
+      <div className="flex-1 flex flex-col min-w-0 overflow-hidden">
+        <header className="lg:hidden bg-white border-b border-gray-200 px-4 py-3 flex items-center justify-between sticky top-0 z-30">
+          <div className="flex items-center gap-3">
+            <button
+              onClick={() => setMobileSidebarOpen(true)}
+              className="p-2 -ml-2 rounded-md hover:bg-gray-100 text-gray-700"
+            >
+              <MenuOutlined className="text-lg" />
+            </button>
+            <h1 className="font-semibold text-gray-900">QR Campaign</h1>
+          </div>
+        </header>
+
+        <main className="flex-1 overflow-y-auto p-4 md:p-8">
+          <Outlet />
+        </main>
+      </div>
+    </div>
+  )
+}