fix: remove hardcoded 6767 from app metadata and analytics fetch

app/analytics/page.tsx

@@ -43,8 +43,9 @@ interface AnalyticsData {
 }
 
 async function getAnalyticsData(): Promise<AnalyticsData> {
-  const res = await fetch('http://127.0.0.1:6767/api/progress?type=analytics', {
+  const res = await fetch('/api/progress?type=analytics', {
     cache: 'no-store',
+    next: { tags: ['analytics'] },
   })
   if (!res.ok) {
     throw new Error('Failed to fetch analytics')

app/layout.tsx

@@ -20,7 +20,7 @@ export const metadata: Metadata = {
   openGraph: {
     type: 'website',
     locale: 'en_US',
-    url: 'http://localhost:6767',
+    url: process.env.NEXT_PUBLIC_APP_URL || 'http://localhost:6969',
     siteName: 'OfflineAcademy',
     title: 'OfflineAcademy — Your Personal Offline Learning Center',
     description: 'A self-hosted, privacy-first learning platform for offline courses.',