Refactor: Create core:api module and set up publishing (#4362)

.github/workflows/publish-packages.yml

@@ -0,0 +1,36 @@
+name: Publish Packages
+
+on:
+  release:
+    types: [created]
+  workflow_dispatch:
+
+jobs:
+  publish:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v6
+        with:
+          submodules: 'recursive'
+
+      - name: Set up JDK 21
+        uses: actions/setup-java@v5
+        with:
+          java-version: '21'
+          distribution: 'jetbrains'
+
+      - name: Setup Gradle
+        uses: gradle/actions/setup-gradle@v5
+        with:
+          cache-encryption-key: ${{ secrets.GRADLE_ENCRYPTION_KEY }}
+
+      - name: Publish to GitHub Packages
+        run: ./gradlew :core:api:publish :core:model:publish :core:proto:publish
+        env:
+          GITHUB_ACTOR: ${{ github.actor }}
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}