a18f6caa9b
Full integration following SeverPay patterns: - API client with Basic Auth, idempotency, HMAC webhook verification - PayPearPaymentMixin with create, webhook, finalize (all side effects), status check - CRUD, model, migration (0058), PaymentMethod.PAYPEAR enum - Webhook endpoint, cabinet topup, bot handler, payment verification - Sub-options: bank_card, sbp, sberpay, tpay - Config: PAYPEAR_ENABLED, PAYPEAR_SHOP_ID, PAYPEAR_SECRET_KEY, etc.