Remove next-intl localization infrastructure

Strips out the i18n layer (next-intl, message files, language switcher,
provider) to reduce complexity. Nav components now use plain English strings.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/components/layouts/jury-nav.tsx

@@ -4,7 +4,6 @@ import { BookOpen, ClipboardList, GitCompare, Home, Trophy } from 'lucide-react'
 import { RoleNav, type NavItem, type RoleNavUser } from '@/components/layouts/role-nav'
 import { trpc } from '@/lib/trpc/client'
 import { Badge } from '@/components/ui/badge'
-import { useTranslations } from 'next-intl'
 
 interface JuryNavProps {
   user: RoleNavUser
@@ -43,30 +42,29 @@ function RemainingBadge() {
 }
 
 export function JuryNav({ user }: JuryNavProps) {
-  const t = useTranslations('nav')
   const navigation: NavItem[] = [
     {
-      name: t('dashboard'),
+      name: 'Dashboard',
       href: '/jury',
       icon: Home,
     },
     {
-      name: t('assignments'),
+      name: 'Assignments',
       href: '/jury/assignments',
       icon: ClipboardList,
     },
     {
-      name: t('awards'),
+      name: 'Awards',
       href: '/jury/awards',
       icon: Trophy,
     },
     {
-      name: t('compare'),
+      name: 'Compare',
       href: '/jury/compare',
       icon: GitCompare,
     },
     {
-      name: t('learningHub'),
+      name: 'Learning Hub',
       href: '/jury/learning',
       icon: BookOpen,
     },