#432 Publish SNAPSHOTs to GH Packages from CI

Add a publish-gh-packages job to gradle-build.yml that runs after
build-artifacts succeeds and pushes all four artifacts plus the
plugin marker to GitHub Packages.

Triggers only on push events to feature/* or bugfix/* branches —
those are the refs git-versioning rewrites to <slug>-SNAPSHOT
coordinates. develop and main fall through to gradle.properties'
static 2.0.0-rcN and would conflict with already-published
release versions, so we skip them here.

The job uses the auto-injected secrets.GITHUB_TOKEN (no PAT needed
for in-repo publishing) and github.actor as the username. The
conditional credential block in build.gradle picks them up; without
the env vars set (e.g. on PRs from forks) the GitHubPackages repo
isn't registered and the job's gradle invocation would be a no-op,
but the 'if:' gate prevents that path from running at all.

Author: ascheman

.github/workflows/gradle-build.yml

@@ -18,6 +18,39 @@ jobs:
     secrets:
       SONAR_TOKEN: ${{ secrets.SONAR_TOKEN }}
 
+  publish-gh-packages:
+    # Publish per-branch SNAPSHOTs to GitHub Packages so downstream consumers
+    # can pull a feature/bugfix branch before it merges. Only runs on push
+    # events to feature/bugfix branches (git-versioning's SNAPSHOT regex);
+    # develop and main fall through to the static gradle.properties version
+    # and would conflict with already-published releases.
+    needs: build-artifacts
+    if: github.event_name == 'push' && (startsWith(github.ref, 'refs/heads/feature/') || startsWith(github.ref, 'refs/heads/bugfix/'))
+    runs-on: ubuntu-latest
+    permissions:
+      packages: write
+      contents: read
+    steps:
+      - name: Check out
+        uses: actions/checkout@v5
+
+      - name: Setup Java
+        uses: actions/setup-java@v5
+        with:
+          distribution: temurin
+          java-version: '17'
+
+      - name: Setup Gradle
+        uses: gradle/actions/setup-gradle@v4
+        with:
+          cache-read-only: true
+
+      - name: Publish SNAPSHOT to GitHub Packages
+        env:
+          GITHUB_USER: ${{ github.actor }}
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: ./gradlew publishAllPublicationsToGitHubPackagesRepository --no-daemon
+
   post-build:
     needs: build-artifacts
     runs-on: ubuntu-latest