Belgian payroll declarations can now be sent to and synchronized with the official ONSS portal through a dedicated SFTP connection. This reduces manual handling of DmfA files, improves compliance workflows, and includes fixes that make declaration generation and signature handling more reliable.

The Point of Sale order sync now only clears orders that were actually synchronized. This prevents pending, unsynced orders from being accidentally removed, reducing the risk of lost sales data.

In `syncAllOrders`, we can specify which orders should be synced using options.
This means that not all pending orders need to be synced at once. 
However, `clearPendingOrder` currently removes all pending orders, 
even those that haven't been synced, leading to order loss.

This commit ensures that only synced orders are removed from pendingOrders.

Task: 4702408