feat(verification): add XML Schema, OpenAPI, and Avro Docker verification targets

[apoorv7g]

This PR extends the Docker based codegen verification harness with three new schema targets: XML Schema, OpenAPI, and Avro. Each target gets a Docker image, an entrypoint that generates from the corpus and runs an external validator, a local Mocha verification test, registration in verification/docker/targets.json and scripts/verification/docker-run.js, a verify:docker:<target> npm script, and a matrix entry in .github/workflows/verify-codegen.yml.

Where generated output is known to be rejected by the external tool because of existing visitor limitations, the affected case and target pairs are skipped with an explicit reason (same pattern as protobuf, graphql, rust, and java).

Changes

Shared wiring

• Registered xmlschema, openapi, and avro in verification/docker/targets.json.
• Extended scripts/verification/docker-run.js TARGETS to include all three.
• Added npm scripts: verify:docker:xmlschema, verify:docker:openapi, verify:docker:avro.
• Added all three targets to the verify-codegen GitHub Actions matrix.
• Extended per target skip documentation in test/verification/cases.js and, for the Docker corpus metamodel case, in verification/corpus/manifest.json.

XML Schema (xmlschema)

• Added verification/docker/xmlschema/Dockerfile and entrypoint.sh.
• Image installs libxml2-utils and downloads the W3C XML Schema for Schemas (XMLSchema.xsd) at build time.
• Entrypoint generates CTO to .xsd via CLI target XMLSchema, then validates each file with xmllint --noout --schema against the bundled meta schema.
• Added test/verification/xmlschema.validate.test.js: generates with XmlSchemaVisitor, validates with xmllint --schema. Locally skips the suite when xmllint is not installed. Falls back to the W3C URL if the local meta schema path is missing (override with XMLSCHEMA_META_SCHEMA).

OpenAPI (openapi)

• Added verification/docker/openapi/Dockerfile, entrypoint.sh, and redocly.yaml (extends: minimal).
• Image installs @redocly/cli@1.34.3 globally. Entrypoint generates via CLI target OpenApi, then runs redocly lint on each openapi.json.
• Added test/verification/openapi.validate.test.js: generates with OpenApiVisitor, lints with the local @redocly/cli package (devDependency) via require.resolve and node, so no global CLI install is required on developer machines.
• Uses the same verification/docker/openapi/redocly.yaml config locally (override with REDOCLY_CONFIG).

Avro (avro)

• Added verification/docker/avro/Dockerfile and entrypoint.sh.
• Image installs a JRE and downloads Apache avro-tools-1.12.0.jar. Entrypoint generates via CLI target Avro, then runs java -jar … idl on each .avdl.
• Added test/verification/avro.validate.test.js: mirrors the Java Jackson jar pattern. Downloads avro-tools-1.12.0.jar from Maven Central into verification/templates/ on first run when missing (override with AVRO_TOOLS_JAR). Only skips when Java is not installed.
• Gitignored verification/templates/avro-tools-*.jar (same approach as jackson-annotations-*.jar).

Skips (what and why)

These skips document known visitor output issues. They are not Docker or harness bugs. Fixing them belongs in follow up visitor PRs (plus snapshot updates).

Avro: illegal versioned namespaces

AvroVisitor emits @namespace("concerto.decorator@1.0.0") (and similar). Avro IDL rejects that namespace because version segments such as 0 are illegal identifiers (SchemaParseException: Illegal name: 0).

Case	Target	Why skipped
metamodel	avro	Generates versioned system namespaces including concerto.decorator@1.0.0
hr_base	avro	Same versioned namespace problem when decorator or system models are present
hr_integration	avro	Same
stringlength	avro	Same
model-base	avro	Same
agreement	avro	Same
circular	avro	Same

Docker corpus: metamodel case also skips avro for the same reason in verification/corpus/manifest.json.

OpenAPI: $decorators and invalid schema nesting

OpenApiVisitor embeds JSON Schema from JSONSchemaVisitor. That payload includes $decorators (and in some graphs invalid schema nesting) which Redocly's OpenAPI struct rules reject. Component map keys with @ in FQNs also warn under Redocly naming rules; the hard failures that forced skips are the struct errors.

Case	Target	Why skipped
hr_integration	openapi	$decorators and invalid schema nesting fail OpenAPI struct validation
model-base	openapi	$decorators fail OpenAPI struct validation
agreement	openapi	$decorators fail OpenAPI struct validation

Cases that still run for OpenAPI (for example metamodel, hr_base, stringlength, circular) lint clean under the current minimal Redocly config.

Unrelated existing skips (unchanged intent)

Other skips already present for protobuf, graphql, rust, java, and csharp remain; this PR does not change their meaning. New avro / openapi entries were added alongside them where needed.

Flags

• XML Schema local tests require xmllint (libxml2). Without it, those tests are pending rather than failing.
• Avro local tests require a JRE. The tools jar is downloaded automatically like Jackson annotations for Java verification.
• OpenAPI local tests use @redocly/cli from devDependencies; Docker still installs it globally in the target image.
• Docker images download remote assets at build time (W3C XMLSchema.xsd, Maven/Apache avro-tools, npm @redocly/cli).
• Skipped case and target pairs should be revisited when AvroVisitor sanitizes versioned namespaces and when OpenAPI generation stops emitting non OAS $decorators (or maps them to x- extensions).

Screenshots or Video

N/A. Verification is exercised via Mocha (npm run test:verify) and Docker (npm run verify:docker:xmlschema, verify:docker:openapi, verify:docker:avro).

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

[apoorv7g]

@DianaLease @ekarademir and if possible @mttrbrts , please review and approve this, Avro and OpenAPI fixes can be done after GSoC Period.