feat: update Docker configuration and CI/CD workflows for local image builds

.gitea/workflows/build.yml

@@ -0,0 +1,25 @@
+name: Build Production Images
+
+on:
+  pull_request_review:
+    types: [submitted]
+
+jobs:
+  build:
+    name: Build Production Images
+    if: github.event.review.state == 'approved' && github.event.pull_request.base.ref == 'main'
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          github-server-url: http://gitea.lab
+          ref: ${{ github.event.pull_request.head.sha }}
+
+      - name: Verify Docker CLI
+        run: docker version
+
+      - name: Build backend image
+        run: docker build -t condado-newsletter-backend:latest -f backend/Dockerfile ./backend
+
+      - name: Build frontend image
+        run: docker build -t condado-newsletter-frontend:latest -f frontend/Dockerfile ./frontend