SEPA Transfer v1.0

This extension is self-contained and works out of the box with no external
services, no API keys, and no Composer packages.

Optional (not required for normal use,):

- German bank directory update — the bundled German bank directory already
contains the largest banks. To regenerate the complete directory, the
included tool (tools/update-blz.php) can process the official, free bank-code
file published by Deutsche Bundesbank:
https://www.bundesbank.de/de/aufgaben/unbarer-zahlungsverkehr/serviceangebot/bankleitzahlen
This is optional; the gateway works fully without it, and a missing bank
never blocks a payment (within SEPA the IBAN alone is sufficient).

Requirements: Paymenter 1.5.x, PHP 8.2+ with the GD extension for QR images,
invoices in EUR.