Komsco Practice

Build me a backend system for managing local currency vouchers, covering the entire lifecycle from issuance to settlement. The system must ensure financial integrity using double-entry bookkeeping (DEBIT/CREDIT) and maintain audit trails by using compensating transactions instead of deletions. I need to implement robust concurrency control using distributed locks, like Redisson. The architecture should be modular, handling distinct domains like Region management (with configurable policies), Member management (including JWT authentication and role-based access), and Merchant lifecycle management. Key flows involve purchase, partial usage, and settlement, which must be transactionally consistent. Please structure the code using Kotlin and Spring Boot, utilizing JPA for persistence and Docker Compose for local setup.