[JAVA-01] Establish supported Java baseline, build, coordinates, and code generation

[jaavid]

Resolution

Completed for the initial generated Java baseline against the current 1.0.0-draft public contract.

Evidence

• Java baseline is explicitly Java 17+.
• Planned coordinates are io.corelink:corelink-sdk with prerelease version 0.1.0-SNAPSHOT.
• .corelink-contract.json pins immutable contract tag v1.0.0-draft, commit 5bdc07b80c8acbd0617b75e2d7ae3edd17f6324b, and OpenAPI blob 11cd7034f2b6dc736e23a4cf36242a34f0d637e5.
• CODEGEN.md defines the exact OpenAPI Generator 7.12.0 command, package layout and Maven build path.
• Blacksmith Generated SDK Conformance generates the Java client from the immutable contract and runs mvn -B -DskipTests package.
• Blacksmith run 33277037833 completed successfully on commit ee5cca2fde0f5fd001aad65d0db52b3ebfb2d280.
• README now classifies the repository as an Experimental / Generated Baseline rather than claiming a supported public artifact.

Acceptance criteria

• Supported Java runtime baseline is defined.
• Build/tooling and package coordinates are defined.
• Generation is reproducible from immutable tagged contract provenance.
• Generated client compiles successfully in Blacksmith CI.
• Provider-specific models remain outside the public SDK contract.
• Current package maturity is documented accurately; no Maven Central/Stable claim is made.

JAVA-02 owns auth/tenant/error/retry/Spring ergonomics and conformance. JAVA-03 owns signed prerelease/stable publication.