Add CI to test and build theme

.github/workflows/ci.yml

@@ -0,0 +1,63 @@
+name: CI
+
+on:
+  pull_request:
+    branches: ['**']
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Set up Java
+        uses: actions/setup-java@v4
+        with:
+          distribution: temurin
+          java-version: '20'
+
+      - name: Set up Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: '20'
+
+      - name: Install pnpm
+        uses: pnpm/action-setup@v3
+        with:
+          version: 10
+          run_install: false
+
+      - name: Get pnpm store path
+        id: pnpm-cache
+        run: echo "store=$(pnpm store path)" >> "$GITHUB_OUTPUT"
+
+      - name: Cache pnpm store
+        uses: actions/cache@v4
+        with:
+          path: ${{ steps.pnpm-cache.outputs.store }}
+          key: pnpm-${{ runner.os }}-${{ hashFiles('**/pnpm-lock.yaml') }}
+          restore-keys: pnpm-${{ runner.os }}-
+
+      - name: Install dependencies
+        run: pnpm install --frozen-lockfile
+
+      - name: Run Maven tests
+        run: pnpm test
+
+      - name: Build theme
+        run: pnpm build:jar
+
+      - name: Commit build artifacts
+        if: github.event_name == 'push'
+        run: |
+          git config user.name "github-actions[bot]"
+          git config user.email "github-actions[bot]@users.noreply.github.com"
+          git add -f target/
+          if git diff --cached --quiet; then
+            echo "No changes to commit"
+          else
+            git commit -m "chore: update build artifacts [skip ci]"
+            git push
+          fi