This change adds a development-only way to load Point of Sale tour tests so teams can run synchronization scenarios across multiple browser sessions. It helps validate order, payment, and restaurant workflow synchronization more reliably without affecting normal users, since the test tools load only when explicitly enabled in the POS URL.

Before we had no solution to test the synchronisation of the pos. In classic tours websocket are not supported. And we cannot launch two tours in parallel.

This commit add the possibility to load test assets in the PoS during our development. That's allow us to launch tour in loop in two different browser and test the synchronisation by creating orders, payment etc.

Tour assets are only added by adding `&tours=True` in the URL of the PoS interface.

This change updates the Dutch SBR tax report wizard, which is used to prepare statutory tax submissions in the Netherlands. The available information is limited because the pull request is still marked as work in progress, but the impact appears focused on improving or correcting that reporting flow.

[WIP]