/cmd
  └── main.go          # Application entry point
/internal
  ├── /disbursement    # Business logic for disbursement
  │   ├── handler.go   # HTTP handler for disbursement
  │   ├── service.go   # Business service logic for disbursement
  │   ├── repository.go # Data repository for user and balance management
  │   └── model.go     # Models for disbursement
  └── /core            # Core entities
      └── user.go      # Core user entity (domain model)