Refine CI artifact promotion and IntelliJ snapshot publishing

[lagergren]

Summary

• convert the snapshot CI path to staged artifact promotion instead of downstream source rebuilds
• make IntelliJ snapshot publishing explicit and manual-only, with stable GitHub snapshot asset names and correct release retargeting
• tighten provenance validation, workflow gating, summaries, and release/process documentation so the branch is safer to merge without changing default master behavior more than necessary
• remove the stale Kotlin JDK split and build all Kotlin/build-logic outputs on JDK 25

What Changed

• commit.yml now stages commit-scoped CI artifacts for the XDK ZIP, consumer Maven repo, snapshot Maven repo, and optional IntelliJ plugin bundle
• integration-test consumes the staged consumer Maven repo artifact instead of rebuilding/publishing locally from source
• publish-snapshot.yml consumes the staged snapshot Maven bundle and staged IntelliJ plugin bundle instead of rebuilding them from source
• Docker and Homebrew continue to promote the CI-built XDK artifact, now with explicit source commit/run provenance validation through the shared download action
• IntelliJ snapshot publishing is no longer automatic on master; it only runs via workflow_dispatch when explicitly requested and only when relevant lang/ or lib_ecstasy/**/*.x changes are present
• GitHub IntelliJ snapshot assets now use stable names per base snapshot version and overwrite in place
• release docs and workflow text were corrected to reflect manual promotion semantics
• Kotlin build-toolchain configuration was simplified to JDK 25 across build logic and lang-side Kotlin outputs

Validation

• default non-IntelliJ / non-publishing CI path remains lean and successful
• manual non-IntelliJ snapshot publication path verified on this branch:
  • XDK snapshot GitHub release asset updated
  • GitHub Packages snapshots published
  • Maven Central Snapshots published
  • Docker downstream workflow succeeded
  • Homebrew downstream workflow succeeded
• manual IntelliJ-enabled snapshot publication path verified on this branch:
  • staged IntelliJ artifact reused downstream
  • JetBrains Marketplace alpha publication succeeded
  • GitHub intellij-plugin-snapshots release updated with stable assets:
    • xtc-intellij-plugin-0.4.4-SNAPSHOT.zip
    • xtc-intellij-plugin-0.4.4-SNAPSHOT.zip.sha256
  • target_commitish now updates automatically to the producing commit
• full root local build after the JDK 25 cleanup succeeded:
  • ./gradlew clean
  • ./gradlew build --console=plain
• representative generated Kotlin/build-logic classfiles were checked on disk and are now Java 25 bytecode

Current Deliverables

• IntelliJ plugin snapshot ZIP on GitHub:
  • https://github.com/xtclang/xvm/releases/tag/intellij-plugin-snapshots
• XDK snapshot ZIP on GitHub:
  • https://github.com/xtclang/xvm/releases/tag/xdk-snapshots
• Docker images on GitHub Container Registry:
  • https://github.com/xtclang/xvm/pkgs/container/xvm
• Homebrew tap repo:
  • https://github.com/xtclang/homebrew-xvm
• Maven snapshot repositories:
  • GitHub Packages: https://maven.pkg.github.com/xtclang/xvm
  • Maven Central Snapshots: https://central.sonatype.com/repository/maven-snapshots

Latest Validated Runs

• Full IntelliJ-enabled source run on current green head:
  • https://github.com/xtclang/xvm/actions/runs/24311953367
• Downstream snapshot publication:
  • https://github.com/xtclang/xvm/actions/runs/24312217071
• Downstream Docker publication:
  • https://github.com/xtclang/xvm/actions/runs/24312217474
• Downstream Homebrew update:
  • https://github.com/xtclang/xvm/actions/runs/24312217827

Remaining Follow-ups

Tracked separately to keep this branch mergeable:

• Release workflows: adopt artifact promotion and gated IntelliJ parity #429 Release workflows: adopt artifact promotion and gated IntelliJ parity
• CI follow-ups: normalize artifact metadata and reduce remaining publication/check noise #430 CI follow-ups: normalize artifact metadata and reduce remaining publication/check noise

Merge Posture

• the core snapshot-path artifact reuse work is complete enough to land
• IntelliJ snapshot publishing is disabled by default and only available through manual workflow dispatch
• the remaining work is release-flow parity, metadata/helper normalization, and CI cleanup/performance, not snapshot-path correctness