feat: integrate Etoplatezhi payment provider
- Add etoplatezhi_service.py with HMAC-SHA512+base64 signature algorithm,
payment URL builder, and callback signature verification
- Add payment mixin with create/process/finalize flow, 12 status mappings
- Add CRUD operations with FOR UPDATE locking, idempotency checks
- Add Telegram handlers with SBP/Card sub-method selection
- Add Alembic migration for etoplatezhi_payments table
- Add config settings (ETOPLATEZHI_ENABLED, PROJECT_ID, SECRET_KEY,
SBP_ENABLED, CARD_ENABLED, display names, min/max amounts)
- Add webhook endpoint with JSON-body signature verification
- Register in payment keyboard, router, utils, backup, method config
Fringg
6524f66da2