Merge PR embabel#25 startup tweaks and remove CURSOR-PR.md (embabel#24)

- Delete CURSOR-PR.md (migrated to README.md previously)
- Fix Dockerfile: add codegen-gradle copy and chmod +x for gradlew
- Make Neo4j ports configurable via NEO4J_HTTP_PORT, NEO4J_BOLT_PORT, NEO4J_HTTPS_PORT
- Add Docker Build Details section to README.md
- Update Environment Variables table with Neo4j port configs

Closes embabel#24
Incorporates changes from PR embabel#25

Author: jmjava