feat(verification): add Java support for Docker-based verification

[apoorv7g]

Add Java to Docker and local verification

This pull request expands verification to include Java alongside the existing compiled targets (TypeScript, Rust, and C#). Generated Java is compiled with javac using Jackson annotations on the classpath, matching what the Java visitor emits today.

Changes

• Added Java to the Docker verification matrix with eclipse-temurin:17-jdk-alpine and javac as the compile step
• Created verification/docker/java/Dockerfile and verification/docker/java/entrypoint.sh to generate and compile Java from the verification corpus
• Registered Java in verification/docker/targets.json with CLI target Java and type compiled
• Added verify:docker:java to package.json and included java in scripts/verification/docker-run.js
• Extended .github/workflows/verify-codegen.yml CI matrix with the java target
• Added test/verification/java.compile.test.js to generate Java locally and verify compilation with javac
• Downloads jackson-annotations from Maven Central on first local test run and during Docker image build
• Updated test/verification/cases.js with a per-case skip for hr_integration when scalar map key/value types are not emitted as Java classes
• Updated verification/corpus/manifest.json so the metamodel case runs for Java in Docker (C# remains skipped)

Flags

• Generated Java references Jackson annotation types (@JsonTypeInfo, @JsonIgnoreProperties, and others), so javac requires jackson-annotations on the classpath
• The Jackson JAR is not committed; it is downloaded into verification/templates/ on first local test run (gitignored) and fetched in the Docker image at build time
• hr_integration is skipped in local Mocha tests because the Java visitor does not emit scalar types such as SSN and Time referenced by map declarations
• npm run verify:docker:java requires a running Docker daemon (for example Docker Desktop on Windows)

Author Checklist

• Ensure you provide a DCO sign-off for your commits using the --signoff option of git commit.
• Vital features and changes captured in unit and/or integration tests
• Commits messages follow AP format
• Extend the documentation, if necessary
• Merging to main from fork:branchname