add docker configuration and gitea workflow for automated image builds

Introduce a multi-stage Dockerfile, docker-compose setup, and a Gitea Actions workflow to automate building and pushing images to the registry. The configuration includes an entrypoint script for persistent logging and a .dockerignore to optimize the build context.

.gitea/workflows/docker.yml

@@ -0,0 +1,55 @@
+name: Build & Publish Docker Image
+
+on:
+  push:
+    branches:
+      - main
+    tags:
+      - "v*"
+
+jobs:
+  build-and-push:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      # Strip "https://" from the server URL to get the registry hostname
+      - name: Resolve registry host
+        id: reg
+        run: |
+          host=$(echo "${{ gitea.server_url }}" | sed 's|https://||;s|http://||;s|/||g')
+          echo "host=$host" >> $GITHUB_OUTPUT
+          echo "image=$host/${{ gitea.repository }}" >> $GITHUB_OUTPUT
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Log in to Gitea registry
+        uses: docker/login-action@v3
+        with:
+          registry: ${{ steps.reg.outputs.host }}
+          username: ${{ secrets.REGISTRY_USER }}
+          password: ${{ secrets.REGISTRY_TOKEN }}
+
+      - name: Extract Docker metadata
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: ${{ steps.reg.outputs.image }}
+          tags: |
+            type=raw,value=latest,enable=${{ gitea.ref == 'refs/heads/main' }}
+            type=semver,pattern={{version}}
+            type=semver,pattern={{major}}.{{minor}}
+            type=sha,prefix=sha-,format=short
+
+      - name: Build and push
+        uses: docker/build-push-action@v6
+        with:
+          context: .
+          push: true
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}
+          cache-from: type=gha
+          cache-to: type=gha,mode=max