ci: Add Gitea Actions workflow for testing and deployment

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.gitea/workflows/ci.yaml

@@ -0,0 +1,59 @@
+name: CI/CD
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+jobs:
+  test:
+    runs-on: linux-amd64
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Set up Go
+        uses: actions/setup-go@v5
+        with:
+          go-version: '1.25.6'
+
+      - name: Download dependencies
+        working-directory: ./backend
+        run: go mod download
+
+      - name: Build
+        working-directory: ./backend
+        run: go build -v ./...
+
+      - name: Test
+        working-directory: ./backend
+        run: go test -v ./...
+
+  build-and-push:
+    runs-on: linux-amd64
+    needs: test
+    if: github.event_name == 'push' && github.ref == 'refs/heads/main'
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Login to Gitea Registry
+        uses: docker/login-action@v3
+        with:
+          registry: gitea.home.hrajfrisbee.cz
+          username: ${{ github.repository_owner }}
+          password: ${{ secrets.REGISTRY_TOKEN }}
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Build and push
+        uses: docker/build-push-action@v5
+        with:
+          context: ./backend
+          file: ./backend/Dockerfile.prod
+          push: true
+          tags: |
+            gitea.home.hrajfrisbee.cz/${{ github.repository }}/backend:latest
+            gitea.home.hrajfrisbee.cz/${{ github.repository }}/backend:${{ github.sha }}