Configure Maven Central and GitHub Packages publishing

- Add distributionManagement to pom.xml for Maven Central (ossrh)
- Update publish.yml workflow:
  - Trigger on release creation instead of git tags
  - Use Maven instead of Gradle for publishing
  - Configure dual publishing to Maven Central and GitHub Packages
  - Add GPG signing support for Maven Central
  - Add proper permissions for GitHub Packages

Required GitHub Secrets:
- MAVEN_USERNAME: Sonatype OSSRH username
- MAVEN_PASSWORD: Sonatype OSSRH password or token
- GPG_PRIVATE_KEY: GPG private key for signing artifacts
- GPG_PASSPHRASE: Passphrase for the GPG key

GitHub Packages uses the automatic GITHUB_TOKEN (no manual setup needed).

Author: kwent

.github/workflows/publish.yml

@@ -1,26 +1,47 @@
-name: Test and Publish to Maven
+name: Publish to Maven Central and GitHub Packages
 
 on:
-  push:
-    tags:
-      - 'v*'
+  release:
+    types: [created]
 
 jobs:
-  test-and-publish:
+  publish:
     runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
     steps:
       - uses: actions/checkout@v6
-      - name: Set up JDK
+
+      - name: Set up JDK for Maven Central
         uses: actions/setup-java@v5
         with:
           java-version: '17'
           distribution: 'temurin'
-      - name: Grant execute permission for gradlew
-        run: chmod +x ./gradlew
+          server-id: ossrh
+          server-username: MAVEN_USERNAME
+          server-password: MAVEN_PASSWORD
+          gpg-private-key: ${{ secrets.GPG_PRIVATE_KEY }}
+          gpg-passphrase: MAVEN_GPG_PASSPHRASE
+          cache: 'maven'
+
       - name: Run tests
-        run: ./gradlew test
-      - name: Publish to Maven
-        run: ./gradlew publish
+        run: mvn --batch-mode --update-snapshots test
+
+      - name: Publish to Maven Central
+        run: mvn --batch-mode deploy -P sign-artifacts
         env:
           MAVEN_USERNAME: ${{ secrets.MAVEN_USERNAME }}
-          MAVEN_PASSWORD: ${{ secrets.MAVEN_PASSWORD }} 
+          MAVEN_PASSWORD: ${{ secrets.MAVEN_PASSWORD }}
+          MAVEN_GPG_PASSPHRASE: ${{ secrets.GPG_PASSPHRASE }}
+
+      - name: Set up JDK for GitHub Packages
+        uses: actions/setup-java@v5
+        with:
+          java-version: '17'
+          distribution: 'temurin'
+
+      - name: Publish to GitHub Packages
+        run: mvn --batch-mode deploy -DaltDeploymentRepository=github::default::https://maven.pkg.github.com/${{ github.repository }}
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }} 

pom.xml

@@ -31,6 +31,17 @@
         </developer>
     </developers>
 
+    <distributionManagement>
+        <repository>
+            <id>ossrh</id>
+            <url>https://oss.sonatype.org/service/local/staging/deploy/maven2/</url>
+        </repository>
+        <snapshotRepository>
+            <id>ossrh</id>
+            <url>https://oss.sonatype.org/content/repositories/snapshots</url>
+        </snapshotRepository>
+    </distributionManagement>
+
     <build>
         <plugins>
            <plugin>