fix: resolve typescript error and lint warnings

- Fix TS2698 in JsonLd.tsx (spread types)
- Clean up unused variable in analytics route

app/stats/api/send/route.ts

@@ -27,7 +27,7 @@ export async function POST(request: NextRequest) {
     let body;
     try {
       body = await request.json();
-    } catch (parseError) {
+    } catch (_parseError) {
       logger.warn('Received malformed or empty JSON in analytics proxy');
       return NextResponse.json({ status: 'ignored_bad_payload' }, { status: 200 });
     }