ci: publish backend image to GHCR

.github/workflows/publish-docker-image.yml

@@ -0,0 +1,51 @@
+name: publish docker image
+
+on:
+  push:
+    tags:
+      - 'v*'
+  workflow_dispatch:
+
+permissions:
+  contents: read
+  packages: write
+
+jobs:
+  publish-backend-image:
+    runs-on: ubuntu-latest
+    name: Publish backend image to GHCR
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Log in to GHCR
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Extract Docker metadata
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: ghcr.io/${{ github.repository_owner }}/openmemory
+          tags: |
+            type=ref,event=tag
+            type=sha,prefix=sha-
+            type=raw,value=latest,enable=${{ github.ref_type == 'tag' }}
+
+      - name: Build and push backend image
+        uses: docker/build-push-action@v5
+        with:
+          context: ./packages/openmemory-js
+          file: ./packages/openmemory-js/Dockerfile
+          push: true
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}
+          cache-from: type=gha
+          cache-to: type=gha,mode=max