account_invoice_supplier_ref_unique

Purpose

This module prevents duplicate vendor bills by enforcing per-supplier uniqueness of supplier invoice numbers.

Features

account.move: Validates that vendor bills or refunds do not reuse a supplier invoice number for the same commercial partner when the company enables the check.
account.move: Introduces a vendor invoice number field on purchase documents for tracking supplier references.
account.move: Copies the vendor invoice number into the communication reference when it was empty.
account.move: Clears vendor references when reversing or duplicating purchase documents to avoid carrying the supplier number over.
res.company: Adds a boolean setting to activate the supplier invoice number uniqueness constraint company-wide.
res.config.settings: Shows the vendor invoice number uniqueness option in the Vendor Bills configuration panel.