Add library-management module: console app evolved into a Spring Boot 4 REST API

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

library-management/scripts/run-all.sh

@@ -0,0 +1,30 @@
+#!/usr/bin/env bash
+# Regenerates every file in output/. Needs JDK 25 and Maven; the first run must be online.
+set -euo pipefail
+cd "$(dirname "$0")/.."
+rm -f output/*.txt
+
+# 01: the single-file console version (the copy attached to the article lives in the WordPress media library)
+mkdir -p /tmp/lm && cp scripts/demo-input.txt /tmp/lm/
+echo "01 console (structured) ..."
+mvn -B -q -DskipTests compile
+java -cp target/classes com.ankurm.library.console.ConsoleApp < scripts/demo-input.txt 2>/dev/null > output/01-console-structured.txt
+
+# 02-06: written by the tests themselves, so each file is also an assertion
+echo "02-06 tests ..."
+mvn -B -q test
+
+# 07: the real server, driven with curl
+echo "07 curl demo ..."
+scripts/run.sh --detach
+scripts/api-demo.sh > output/07-curl-demo.txt
+scripts/stop.sh
+
+# 08: the Boot default we override
+echo "08 open-in-view warning ..."
+scripts/open-in-view-warning.sh > output/08-open-in-view-warning.txt
+
+# 09: the SQL one borrow produces
+echo "09 borrow SQL ..."
+scripts/sql-trace.sh > output/09-borrow-sql.txt
+ls output