feat: add Docker workflows for building and pushing frontend and backend images

.github/workflows/build-push-backend.yml

@@ -0,0 +1,54 @@
+name: Build and Push Backend Docker Image
+
+on:
+  push:
+    branches:
+      - main # Adjust if your default branch is different
+    tags:
+      - 'v*.*.*' # Triggers on version tags like v1.0.0
+  workflow_dispatch: # Allows manual triggering from the Actions tab
+
+jobs:
+  build-and-push:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read      # To checkout the repository
+      packages: write    # To push Docker images to GHCR
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Log in to GitHub Container Registry
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Extract metadata (tags, labels) for Docker
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: ghcr.io/${{ github.repository_owner }}/${{ github.event.repository.name }}/backend
+          tags: |
+            # set latest tag for default branch
+            type=raw,value=latest,enable=${{ github.ref == format('refs/heads/{0}', 'main') }}
+            # tag event 'refs/tags/v1.0.0' will generate 'v1.0.0'
+            type=ref,event=tag
+            # branch event 'refs/heads/main' will generate 'main'
+            type=ref,event=branch
+            # sha
+            type=sha
+
+      - name: Build and push Docker image
+        uses: docker/build-push-action@v6
+        with:
+          context: .
+          file: ./Dockerfile
+          push: ${{ github.event_name != 'pull_request' }} # Do not push on PRs
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}
+          build-args: |
+            VERSION=${{ steps.meta.outputs.version }} # This will be the git tag (e.g. v1.0.0) or branch name or sha
+