fix: resolve Forgejo CI Docker daemon access issues

Fixed two CI/CD issues:

1. Docker daemon not accessible
   - Added explicit dockerd startup step
   - Configured buildx to use docker-container driver
   - Driver creates its own buildkitd instance

2. Node.js punycode deprecation warning
   - Downgraded actions/checkout from v6 to v4
   - v4 is more stable and doesn't use deprecated punycode module

Changes ensure the workflow runs successfully in Forgejo Actions runners
that may not have Docker socket access by default.

.forgejo/workflows/build-deploy.yml

@@ -18,11 +18,22 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout code
-        uses: actions/checkout@v6
+        uses: actions/checkout@v4
+
+      - name: Start Docker daemon
+        run: |
+          # Start Docker daemon in background if not running
+          if ! docker info > /dev/null 2>&1; then
+            sudo dockerd &
+            # Wait for Docker to be ready
+            timeout 30 bash -c 'until docker info > /dev/null 2>&1; do sleep 1; done'
+          fi
 
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v3
         with:
+          driver: docker-container
+          install: true
           buildkitd-config-inline: |
             [registry."docker.io"]
               mirrors = ["docker-mirror.mcintire.me"]