Add Custom Notes to Invoices for Tax Treatments

Customers have expressed a need to add custom notes to their invoices, especially for specific tax treatments like reverse charge VAT. These important details are not always covered by standard VAT rates and require a dedicated space on the invoice. We are looking to implement a new feature that allows users to add a free-text note directly to invoices. This note would appear both within the application and on the exported PDF, ensuring all relevant information is clearly visible to recipients.