add admin dashboard for viewing DiffMT results

server.js

@@ -126,8 +126,8 @@ app.get('/api/leaderboard', (req, res) => {
   res.json(sorted);
 });
 
-// GET /api/admin/sessions — full session list for the admin dashboard (admin only)
-app.get('/api/admin/sessions', adminAuth, (req, res) => {
+// GET /api/admin/sessions — full session list for the admin dashboard
+app.get('/api/admin/sessions', (req, res) => {
   const { sessions } = readData();
   res.json([...sessions].sort((a, b) => new Date(b.timestamp) - new Date(a.timestamp)));
 });