Add: Forgejo CI build workflow (migrated from GitLab CI)

.forgejo/workflows/build.yml

@@ -0,0 +1,41 @@
+name: Build Docker Image
+
+on:
+  push:
+    branches: [main, master]
+
+env:
+  REGISTRY: 192.168.1.100:3000
+  IMAGE: root/daily-briefing
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    container:
+      image: docker:latest
+      volumes:
+        - /var/run/docker.sock:/var/run/docker.sock
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Determine tag
+        id: vars
+        run: |
+          BRANCH="${GITHUB_REF_NAME}"
+          if [ "$BRANCH" = "main" ] || [ "$BRANCH" = "master" ]; then
+            TAG="nightly"
+          else
+            TAG=$(echo "$BRANCH" | sed 's/\//-/g')
+          fi
+          echo "tag=$TAG" >> "$GITHUB_OUTPUT"
+
+      - name: Build and push
+        run: |
+          docker build \
+            -t ${{ env.REGISTRY }}/${{ env.IMAGE }}:${{ steps.vars.outputs.tag }} \
+            -t ${{ env.REGISTRY }}/${{ env.IMAGE }}:${{ github.sha }} \
+            .
+
+          echo "${{ secrets.REGISTRY_PASSWORD }}" | docker login ${{ env.REGISTRY }} -u root --password-stdin
+          docker push ${{ env.REGISTRY }}/${{ env.IMAGE }}:${{ steps.vars.outputs.tag }}
+          docker push ${{ env.REGISTRY }}/${{ env.IMAGE }}:${{ github.sha }}