Add Docker support with Dockerfile and entrypoint

.forgejo/workflows/docker.yml

@@ -0,0 +1,44 @@
+name: Docker
+
+on:
+  push:
+    branches:
+      - master
+    tags:
+      - 'v*'
+
+jobs:
+  build:
+    runs-on: docker
+    steps:
+      - uses: actions/checkout@v3
+
+      - name: Log in to Codeberg registry
+        if: startsWith(github.ref, 'refs/tags/')
+        uses: docker/login-action@v3
+        with:
+          registry: codeberg.org
+          username: ${{ secrets.REGISTRY_USER }}
+          password: ${{ secrets.REGISTRY_TOKEN }}
+
+      - name: Extract version tag
+        if: startsWith(github.ref, 'refs/tags/')
+        id: meta
+        run: echo "tag=${GITHUB_REF#refs/tags/}" >> $GITHUB_OUTPUT
+
+      - name: Build (verify only, no push)
+        if: github.ref == 'refs/heads/master'
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          push: false
+
+      - name: Build and push (tagged release)
+        if: startsWith(github.ref, 'refs/tags/')
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          push: true
+          tags: |
+            codeberg.org/${{ github.repository }}:${{ steps.meta.outputs.tag }}
+            codeberg.org/${{ github.repository }}:latest