[grails-plugin-template-sync]

Syncs common infrastructure files from grails-plugin-template.

Files updated:

• .github/workflows/ (CI, release, release-notes, update-contributors, update-versions —
  combined from the template's own .github/workflows/ and its child-only
  .github/sync/workflows/)
• .github/scripts/ (update-contributors, update-versions, the groovy.sh Docker wrapper that runs them)
• .github/dependabot.yml, renovate.json, release-drafter.yml
• docs/src/docs/index.tmpl (gh-pages version-index template)
• .agents/ (agent skills; .claude symlink created/repaired, replaces legacy .skills/)
• settings.gradle: build-logic/ / conventions/ removed, the config.* plugins mapped to
  org.grails.plugins.gradle:grails-plugin-conventions:1.0.0-RC5,
  and the Grails, asset-pipeline and grails-publish Gradle plugins put on the settings classpath at this
  repository's grailsVersion (the conventions do not bring them, so they work on any Grails line)
• .editorconfig, CONTRIBUTING.md, LICENSE.txt

.sdkmanrc and the Gradle wrapper are not synced — keep them in step yourself (CI fails if
.sdkmanrc's gradle version and gradle/wrapper/gradle-wrapper.properties disagree).

To lock a single file and prevent future syncs, create a <filename>.lock file next to it.
The same works for whole synced trees (.github/workflows/, .github/scripts/) — a lock file
anywhere under one of those directories excludes its namesake from that sync, e.g.
.github/workflows/ci.yml.lock keeps your own ci.yml. A settings.gradle.lock keeps your
settings.gradle untouched, and build-logic.lock / conventions.lock keep those directories.
A workflow named local-*.yml is never touched by this sync at all.

.github/dependency-graph/external-references.yml is never synced — its Maven
coordinates are specific to this repository.