Add multi-arch support (amd64 + arm64) to Docker CI workflow

.github/workflows/docker-image.yml

@@ -21,11 +21,15 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v4
 
-      # Step 2: Set up Docker Buildx for advanced features
+      # Step 2: Set up QEMU for multi-arch builds
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v3
+
+      # Step 3: Set up Docker Buildx for advanced features
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v3
 
-      # Step 3: Log in to GitHub Container Registry
+      # Step 4: Log in to GitHub Container Registry
       - name: Log in to GHCR
         uses: docker/login-action@v3
         with:
@@ -33,7 +37,7 @@ jobs:
           username: ${{ github.actor }}
           password: ${{ secrets.GITHUB_TOKEN }}
 
-      # Step 4: Generate tags and labels from Git metadata
+      # Step 5: Generate tags and labels from Git metadata
       - name: Extract metadata
         id: meta
         uses: docker/metadata-action@v5
@@ -50,11 +54,12 @@ jobs:
             # Tag with short SHA
             type=sha,prefix=
 
-      # Step 5: Build and push the Docker image
+      # Step 6: Build and push the Docker image
       - name: Build and push
         uses: docker/build-push-action@v5
         with:
           context: .
+          platforms: linux/amd64,linux/arm64
           # Only push on main branch and tags, not PRs
           push: ${{ github.event_name != 'pull_request' }}
           tags: ${{ steps.meta.outputs.tags }}