file uploaded path correction

server/routes/upload.js

@@ -33,7 +33,23 @@ const upload = multer({
 
 const router = Router();
 
-router.post('/', requireAuth, upload.single('file'), (req, res) => {
+// Wrap multer for Express 5 — multer v2 doesn't handle Express 5 async errors natively
+function runUpload(req, res) {
+  return new Promise((resolve, reject) => {
+    upload.single('file')(req, res, (err) => {
+      if (err) reject(err);
+      else resolve();
+    });
+  });
+}
+
+router.post('/', requireAuth, async (req, res) => {
+  try {
+    await runUpload(req, res);
+  } catch (err) {
+    const status = err.code === 'LIMIT_FILE_SIZE' ? 413 : 400;
+    return res.status(status).json({ error: err.message, code: err.code || 'UPLOAD_ERROR' });
+  }
   if (!req.file) {
     return res.status(400).json({ error: 'No file uploaded', code: 'VALIDATION' });
   }