Admin: corregir columnas de account_access + enlace al panel en la cuenta

- Este build de AzerothCore usa account_access(AccountID, SecurityLevel), no el
  clásico (id, gmlevel). Se corrigen las 4 consultas (admin.ts, forum-perm.ts,
  forum.ts, admin-users.ts) -> isAdmin/forumIsModerator/gmlevel ahora funcionan.
- account page: enlace destacado al Panel de administración, visible solo si isAdmin.
- i18n es/en: Account.adminPanel.

Verificado: build OK; cuenta de prueba con SecurityLevel 3 (>= ADMIN_GMLEVEL) es admin.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

web-next/app/[locale]/account/page.tsx

@@ -2,6 +2,7 @@ import { getTranslations, setRequestLocale } from 'next-intl/server'
 import { redirect, Link } from '@/i18n/navigation'
 import { getSession } from '@/lib/session'
 import { getAccountDashboard } from '@/lib/account'
+import { isAdmin } from '@/lib/admin'
 import { LogoutButton } from '@/components/LogoutButton'
 
 export const dynamic = 'force-dynamic'
@@ -16,6 +17,7 @@ export default async function AccountPage({ params }: { params: Promise<{ locale
   if (!session.username) redirect({ href: '/select-account', locale })
 
   const data = await getAccountDashboard(session)
+  const admin = await isAdmin(session)
 
   const card = 'nw-card'
 
@@ -26,6 +28,16 @@ export default async function AccountPage({ params }: { params: Promise<{ locale
         <LogoutButton className="rounded border border-amber-900/60 px-3 py-1 text-sm text-amber-200 hover:text-amber-400" />
       </div>
 
+      {admin && (
+        <Link
+          href="/admin"
+          className="mb-6 flex items-center justify-between gap-3 rounded-lg border border-nw-gold/50 bg-nw-gold/10 px-4 py-3 text-sm font-semibold text-nw-gold-light transition hover:bg-nw-gold/20"
+        >
+          <span>🛡️ {t('adminPanel')}</span>
+          <span aria-hidden>→</span>
+        </Link>
+      )}
+
       <div className="grid gap-4 sm:grid-cols-2">
         <section className={card}>
           <div className="space-y-1 text-sm">