Added Docker workflow

.gitea/workflows/docker.yml

@@ -0,0 +1,47 @@
+name: Build & Push Docker Image
+
+on:
+  push:
+    tags:
+      - "v*"            # triggers on v0.1.0, v1.0.0, etc.
+  workflow_dispatch:    # allow manual trigger from Gitea UI
+
+env:
+  REGISTRY: git.azuze.fr
+  IMAGE: git.azuze.fr/kawa/cubeadmin
+
+jobs:
+  build-and-push:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Extract version tag
+        id: meta
+        run: |
+          TAG="${GITHUB_REF_NAME}"          # e.g. v0.1.0
+          VERSION="${TAG#v}"                # strip leading v → 0.1.0
+          echo "tag=${TAG}"       >> $GITHUB_OUTPUT
+          echo "version=${VERSION}" >> $GITHUB_OUTPUT
+
+      - name: Log in to Gitea container registry
+        uses: docker/login-action@v3
+        with:
+          registry: ${{ env.REGISTRY }}
+          username: ${{ secrets.REGISTRY_USER }}
+          password: ${{ secrets.REGISTRY_TOKEN }}
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Build and push
+        uses: docker/build-push-action@v6
+        with:
+          context: .
+          push: true
+          tags: |
+            ${{ env.IMAGE }}:latest
+            ${{ env.IMAGE }}:${{ steps.meta.outputs.version }}
+          cache-from: type=gha
+          cache-to: type=gha,mode=max