Payment Bacen PIX

This module adds a new payment provider called "Bacen (PIX)" to the Payment Acquirers list. Once configured with the bank credentials (Email, Client ID, Client Secret, Basic, PIX Key, Dev APP KEY and an expiration time in seconds), users can enable it and offer PIX as a payment option to customers.

When a customer pays, Odoo creates a PIX charge at the bank and shows a QR code on the payment page. The transaction stays in draft until the customer pays; while waiting it shows a pending confirmation message. A "Check Status" button on the payment transaction form lets users manually refresh the status from the bank.

Statuses are updated automatically: created becomes pending, paid becomes done, rejected becomes error, and expired cancels the transaction and resets and cancels the related invoices. A public webhook receives the bank's notifications and validates them with a secure signature before updating the transaction.

The module also computes payment fees based on the acquirer's fee settings, and adds PIX-specific fields (QR code, amount, currency, expiration, transaction id, PIX key, status) to payment transactions. It touches payment.acquirer and payment.transaction.