fix: Uses docker binary

.forgejo/workflows/images.yml

@@ -11,12 +11,25 @@ jobs:
       - name: Checkout repository
         uses: actions/checkout@v4
 
+      - name: Check Docker CLI and daemon
+        run: |
+          if ! command -v docker >/dev/null 2>&1; then
+            echo "::error::docker CLI not found in PATH on this runner"
+            exit 1
+          fi
+
+          if ! docker info >/dev/null 2>&1; then
+            echo "::error::docker daemon is not reachable (check /var/run/docker.sock or DOCKER_HOST)"
+            docker version || true
+            env | grep '^DOCKER' || true
+            ls -l /var/run/docker.sock || true
+            exit 1
+          fi
+
       - name: Login to Container Registry
-        uses: docker/login-action@v3
-        with:
-          registry: git.hamburg.ccc.de
-          username: ${{ secrets.REGISTRY_USERNAME }}
-          password: ${{ secrets.REGISTRY_TOKEN }}
+        if: github.event_name == 'push'
+        run: |
+          echo "${{ secrets.REGISTRY_TOKEN }}" | docker login git.hamburg.ccc.de -u "${{ secrets.REGISTRY_USERNAME }}" --password-stdin
       
       - name: Set image tags
         id: vars