Add AI-check details modal on worker page and raise backup upload limit

server.js

@@ -749,6 +749,8 @@ async function aiCorrectText(text) {
   }
 }
 
+const BACKUP_UPLOAD_LIMIT_MB = parseInt(process.env.BACKUP_UPLOAD_LIMIT_MB || '500', 10);
+
 const uploadBackup = multer({
   storage: multer.diskStorage({
     destination: (_, __, cb) => {
@@ -760,7 +762,7 @@ const uploadBackup = multer({
       cb(null, `backup-${Date.now()}${ext}`);
     },
   }),
-  limits: { fileSize: 50 * 1024 * 1024 },
+  limits: { fileSize: BACKUP_UPLOAD_LIMIT_MB * 1024 * 1024 },
 });
 
 const SAFE_NAME = /^[\w,.()-]+$/;
@@ -2633,6 +2635,7 @@ app.get('/api/ai/status', requireAdmin, async (_, res) => {
     ),
     pool.query(
       `SELECT e.id, e.student_name, e.ai_status, e.ai_checked_at, e.ai_error, g.name AS group_name,
+              e.description_original, e.description_ai,
               (e.description_ai IS NOT NULL AND e.description_original IS NOT NULL AND e.description_ai <> e.description_original) AS changed
        FROM entries e JOIN groups g ON g.id = e.group_id
        WHERE e.ai_checked_at IS NOT NULL AND e.deleted_at IS NULL