fix(web): tDashboard is not defined — 補上 useTranslations('dashboard')

ReferenceError 導致 web pod crash loop。
page.tsx 用了 tDashboard() 但沒宣告。

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

apps/web/src/app/[locale]/page.tsx

@@ -23,6 +23,7 @@ import { AppLayout } from '@/components/layout'
 export default function Home({ params }: { params: { locale: string } }) {
   // eslint-disable-next-line @typescript-eslint/no-unused-vars
   const t = useTranslations()
+  const tDashboard = useTranslations('dashboard')
   // eslint-disable-next-line @typescript-eslint/no-unused-vars
   const locale = params.locale