Replaced custom repository logic with Jakarta Data interfaces to reduce boilerplate and enhance compile-time query validation. Removed `AbstractRepository` and introduced `TransactionRunner` for consistent transactional support. Updated all repository facades to delegate query operations to generated interfaces while retaining the same API, ensuring backward compatibility. Added dependencies for `jakarta.data-api` and Hibernate's `hibernate-processor` for annotation-based query generation. Verified functional parity and improved testability across the repository layer.
