Add Forgejo build workflow for Docker image push

.forgejo/workflows/build.yml

@@ -0,0 +1,41 @@
+name: Build and Push Docker Image
+on:
+  push:
+    branches: [main]
+    tags: ['v*']
+
+jobs:
+  build:
+    runs-on: docker
+    container:
+      image: catthehacker/ubuntu:act-latest
+    steps:
+      - uses: https://data.forgejo.org/actions/checkout@v4
+
+      - name: Set up Docker Buildx
+        uses: https://data.forgejo.org/docker/setup-buildx-action@v3
+
+      - name: Login to Forgejo Registry
+        uses: https://data.forgejo.org/docker/login-action@v3
+        with:
+          registry: forge.lvl0.xyz
+          username: ${{ github.actor }}
+          password: ${{ secrets.REGISTRY_TOKEN }}
+
+      - name: Determine tags
+        id: meta
+        run: |
+          if [[ "${{ github.ref }}" == refs/tags/v* ]]; then
+            TAG="${{ github.ref_name }}"
+            echo "tags=forge.lvl0.xyz/lvl0/buckets:${TAG},forge.lvl0.xyz/lvl0/buckets:latest" >> $GITHUB_OUTPUT
+          else
+            echo "tags=forge.lvl0.xyz/lvl0/buckets:latest" >> $GITHUB_OUTPUT
+          fi
+
+      - name: Build and push
+        uses: https://data.forgejo.org/docker/build-push-action@v5
+        with:
+          context: .
+          file: Dockerfile
+          push: true
+          tags: ${{ steps.meta.outputs.tags }}