Fix jwt-token

client/src/pages/Devices.jsx

@@ -586,13 +586,21 @@ const DeviceModal = ({ device, onClose, onSave }) => {
         
         await api.put(`/devices/${device.id}`, updateData);
       } else {
-        // Create new device - include all fields, convert empty strings to null
+        // Create new device - include all fields, handle empty values properly
         const createData = { ...formData };
+        
+        // Convert empty strings to null for numeric fields, remove empty strings for optional string fields
         Object.keys(createData).forEach(key => {
           if (createData[key] === '') {
-            createData[key] = null;
+            if (['geo_lat', 'geo_lon', 'heartbeat_interval'].includes(key)) {
+              createData[key] = null;
+            } else if (['firmware_version', 'notes', 'location_description', 'name'].includes(key)) {
+              // Remove empty optional string fields instead of sending empty strings
+              delete createData[key];
+            }
           }
         });
+        
         await api.post('/devices', createData);
       }
       onSave();