Add Payment Request → bank API → status polling workflow:
- payment_api.py: send transfers, poll status, cancel, sync bank codes
- Kapital Bank Payment doctype for tracking transfer status
- Kapital Bank Bank Code doctype for transfer routing
- Client-side buttons on Payment Request and Payment Order
- PaymentRequest.before_submit override to survive wkhtmltopdf failures
- Custom fields on Bank Account (kb_bank_code) and Payment Request
- Improved HTTP error handling in BIRBankClient
- Updated CLAUDE.md with full architecture documentation
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Ali