Release Central Metadata Gate PRD

Context

• Release 0.22.2 failed in publish due to missing <developers> metadata.
• We need to fail earlier during prepare-release before creating/pushing a release commit.
• Constraint: avoid adding Python-based XML parsing; prefer bash + Maven.

Goals

• Add a pre-publish metadata gate in release preparation.
• Validate Central-required metadata for all published modules.
• Keep implementation dependency-light (bash + Maven only).

Non-Goals

• Do not change Maven Central publication mode (autoPublish=true).
• Do not replace existing release note/version logic in prepare-release.sh.

Requirements

• Check effective metadata for:
  • ta4j-parent (root)
  • ta4j-core
  • ta4j-examples
• Required fields (non-empty):
  • project.name
  • project.description
  • project.url
  • project.licenses[0].name
  • project.scm.connection
  • project.scm.url
  • project.developers[0].id
  • project.developers[0].name
• Gate must fail workflow with actionable error messages.
• Gate must run before Release X.Y.Z commit creation.

Design

• Add scripts/validate-central-metadata.sh.
• Script uses mvn -q help:evaluate -DforceStdout to evaluate each expression per module.
• Missing or invalid expression values are accumulated and printed as ::error::.
• Exit non-zero if any required metadata is missing.
• Wire script into prepare-release.yml after versions:set/versions:commit for release, before release commit.

Test Plan

• Add shell tests in scripts/tests/test_validate_central_metadata.sh:
  • passes for complete metadata
  • fails when parent POM lacks developers
  • fails when developer id/name missing
• Execute targeted shell tests.
• Run full mandatory build script before completion.

Checklist

• Add validator script
• Add/adjust workflow step
• Add shell tests
• Update changelog
• Run targeted tests
• Run full build script
• Archive this PRD to docs/archive/