Stage 2 console classes and the shared LoanPolicy, then a Spring Boot 4.1.2 + JPA API (H2, @Version optimistic locking, problem+json errors). Tests write output/ transcripts while asserting the same numbers; scripts regenerate everything. Co-Authored-By: Claude Sonnet 5.5 <[email protected]> Claude-Session: https://claude.ai/code/session_017ic4b4DPL6dtpFg4U4LHc2