refactor: Standardize Umami analytics environment variables to non-public names with fallbacks to NEXT_PUBLIC_ prefixed versions.

app/[locale]/layout.tsx

@@ -8,6 +8,7 @@ import { NextIntlClientProvider } from 'next-intl';
 import { getMessages } from 'next-intl/server';
 import '../../styles/globals.css';
 import { SITE_URL } from '@/lib/schema';
+import { config } from '@/lib/config';
 
 export const metadata: Metadata = {
   metadataBase: new URL(SITE_URL),
@@ -51,7 +52,7 @@ export default async function LocaleLayout({
           <CMSConnectivityNotice />
 
           {/* Sends pageviews for client-side navigations */}
-          <AnalyticsProvider />
+          <AnalyticsProvider websiteId={config.analytics.umami.websiteId} />
         </NextIntlClientProvider>
       </body>
     </html>