Stock Picking Batch Invoice Frequency

This module links delivery batches to automatic invoicing. On each invoice frequency record (the setting that decides how often a customer is invoiced), a new toggle called "Automatic batch invoicing" appears. Only users with invoicing rights see it, and it is shown both in the list of frequencies and on the frequency form.

When the toggle is switched on for a frequency, any sales order using that frequency becomes eligible for automatic invoicing. The trigger is the validation of a delivery batch: as the batch is completed, the system looks at the sales orders behind the deliveries in that batch, keeps only those that are still waiting to be invoiced and whose frequency has the option enabled, then creates the customer invoices and posts them immediately.

• New field on sale.invoice.frequency: "Automatic batch invoicing".
• The behaviour is added to stock.picking.batch when its completion action runs, and to stock.picking validation, so invoices are generated only in that batch context.
• Sales orders that are not yet flagged as "to invoice", or whose frequency does not have the option, are ignored.
• No new menus or reports are added; the change is a setting plus an automatic action during batch validation.