Add backend CI/CD workflow

.gitea/workflows/backend.yml

@@ -0,0 +1,50 @@
+name: Build & Deploy Backend
+
+on:
+  push:
+    branches:
+      - main
+
+jobs:
+  build:
+    runs-on: [psgcicd01]   # your central build runner
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v3
+
+      - name: Set up JDK 17
+        uses: actions/setup-java@v3
+        with:
+          distribution: 'temurin'
+          java-version: '17'
+
+      - name: Build with Gradle
+        run: ./gradlew clean build -x test
+
+      - name: Upload artifact
+        uses: actions/upload-artifact@v3
+        with:
+          name: backend-jar
+          path: build/libs/*.jar
+
+  deploy:
+    runs-on: [psgbuild01]   # your backend host runner
+    needs: build
+    steps:
+      - name: Download artifact
+        uses: actions/download-artifact@v3
+        with:
+          name: backend-jar
+          path: /home/sonder/deploy
+
+      - name: Stop service
+        run: sudo systemctl stop ld-sysinfo-server || true
+
+      - name: Deploy new jar
+        run: |
+          sudo mkdir -p /opt/ld-sysinfo-server
+          sudo cp /home/sonder/deploy/*.jar /opt/ld-sysinfo-server/app.jar
+          sudo chown sonder:sonder /opt/ld-sysinfo-server/app.jar
+
+      - name: Start service
+        run: sudo systemctl start ld-sysinfo-server