Migrate from old OSS Sonatype to new Maven Central deployment

[Copilot]

This PR migrates the project from the legacy OSS Sonatype deployment infrastructure (s01.oss.sonatype.org) to the new Maven Central publishing system (central.sonatype.com).

Changes

Distribution Management URLs

Updated the distributionManagement section in pom.xml to use the new Maven Central endpoints:

• Snapshot repository: https://s01.oss.sonatype.org/content/repositories/snapshots → https://central.sonatype.com/
• Release repository: https://s01.oss.sonatype.org/service/local/staging/deploy/maven2/ → https://central.sonatype.com/

Maven Plugin Migration

Replaced the deprecated Nexus Staging plugin with the new Central Publishing plugin:

• Old: org.sonatype.plugins:nexus-staging-maven-plugin:1.7.0
• New: org.sonatype.central:central-publishing-maven-plugin:0.7.0

Plugin Configuration Updates

Updated the plugin configuration to match the new Central Publishing plugin requirements:

• serverId → publishingServerId
• autoReleaseAfterClose → autoPublish
• Removed nexusUrl (no longer needed)
• Added waitUntil: published for synchronous publishing

Compatibility

The existing GitHub Actions workflows (release_deploy.yml and snapshot_deploy.yml) continue to work without modification, as they already use the correct credential names (OSSRH_USERNAME and OSSRH_TOKEN) that are compatible with the new Maven Central system.

Testing

• ✅ Build compiles successfully
• ✅ Tests pass
• ✅ Source and Javadoc artifacts are generated correctly
• ✅ New plugin downloads and integrates properly

This migration ensures the project can continue publishing to Maven Central using the modern publishing infrastructure.

Original prompt

Please migrate the old oss.sonartype deployment to the new maven central deployment. Assume OSSRH_USERNAME & OSSRH_TOKEN already have the correct credentials for the new deployment.

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