ci: add PR validation workflow with Conventional Commits check

- Add .gitea/workflows/pr-validation.yml with 4 validation jobs
- Validate PR titles follow Conventional Commits format
- Check Dockerfile and nginx.conf syntax
- Run integration tests (build image, test container, verify pages load)
- Verify required files exist and HTTrack artifacts excluded
- Update copilot-instructions.md with PR validation details

.gitea/workflows/pr-validation.yml

@@ -0,0 +1,196 @@
+name: Pull Request Validation
+
+on:
+  pull_request:
+    types: [opened, edited, synchronize, reopened]
+
+jobs:
+  validate-pr-title:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Validate PR title follows Conventional Commits
+        run: |
+          PR_TITLE="${{ github.event.pull_request.title }}"
+          echo "Validating PR title: $PR_TITLE"
+          
+          # Conventional Commits pattern: type(scope): description
+          # Types: feat, fix, docs, style, refactor, perf, test, chore, ci, build, revert
+          PATTERN="^(feat|fix|docs|style|refactor|perf|test|chore|ci|build|revert)(\(.+\))?: .+"
+          
+          if echo "$PR_TITLE" | grep -qE "$PATTERN"; then
+            echo "✅ PR title follows Conventional Commits format"
+            exit 0
+          else
+            echo "❌ PR title does not follow Conventional Commits format"
+            echo ""
+            echo "Expected format: <type>(optional scope): <description>"
+            echo ""
+            echo "Valid types:"
+            echo "  - feat:     A new feature"
+            echo "  - fix:      A bug fix"
+            echo "  - docs:     Documentation only changes"
+            echo "  - style:    Code style changes (formatting, missing semi-colons, etc)"
+            echo "  - refactor: Code change that neither fixes a bug nor adds a feature"
+            echo "  - perf:     Performance improvements"
+            echo "  - test:     Adding or updating tests"
+            echo "  - chore:    Changes to build process or auxiliary tools"
+            echo "  - ci:       CI/CD configuration changes"
+            echo "  - build:    Changes to build system or dependencies"
+            echo "  - revert:   Reverts a previous commit"
+            echo ""
+            echo "Examples:"
+            echo "  - feat: add user authentication"
+            echo "  - fix(api): handle null pointer exception"
+            echo "  - docs: update installation instructions"
+            echo "  - ci: add Docker build workflow"
+            exit 1
+          fi
+
+  validate-docker:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Validate Dockerfile syntax
+        run: |
+          if [ -f "Dockerfile" ]; then
+            echo "✅ Dockerfile exists"
+            # Basic syntax check by attempting to parse it
+            docker build --no-cache --target="" -f Dockerfile . 2>&1 | head -5 || true
+            echo "✅ Dockerfile syntax appears valid"
+          else
+            echo "❌ Dockerfile not found"
+            exit 1
+          fi
+
+      - name: Check .dockerignore exists
+        run: |
+          if [ -f ".dockerignore" ]; then
+            echo "✅ .dockerignore exists"
+          else
+            echo "⚠️  Warning: .dockerignore not found (recommended)"
+          fi
+
+      - name: Validate nginx config
+        run: |
+          if [ -f "nginx.conf" ]; then
+            echo "✅ nginx.conf exists"
+            # Test nginx config syntax using alpine nginx image
+            docker run --rm -v "$(pwd)/nginx.conf:/etc/nginx/nginx.conf:ro" nginx:alpine nginx -t
+            echo "✅ nginx.conf syntax is valid"
+          else
+            echo "⚠️  Warning: nginx.conf not found"
+          fi
+
+  build-test:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Build Docker image (no push)
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          push: false
+          tags: karaokepedia:pr-${{ github.event.pull_request.number }}
+          cache-from: type=gha
+          cache-to: type=gha,mode=max
+
+      - name: Test container starts
+        run: |
+          docker build -t karaokepedia:test .
+          CONTAINER_ID=$(docker run -d -p 8080:80 karaokepedia:test)
+          echo "Container started: $CONTAINER_ID"
+          
+          # Wait for container to be healthy
+          echo "Waiting for container to start..."
+          sleep 5
+          
+          # Test homepage
+          if curl -f -s -o /dev/null http://localhost:8080/; then
+            echo "✅ Homepage loads successfully"
+          else
+            echo "❌ Homepage failed to load"
+            docker logs $CONTAINER_ID
+            exit 1
+          fi
+          
+          # Test songs page
+          if curl -f -s -o /dev/null http://localhost:8080/songs.html; then
+            echo "✅ Songs page loads successfully"
+          else
+            echo "❌ Songs page failed to load"
+            exit 1
+          fi
+          
+          # Test assets
+          if curl -f -s -o /dev/null http://localhost:8080/assets/application-b504973bc673ef9f09352588c7d791495f9fa7b652e6bf0d71ea86a094aa4007.css; then
+            echo "✅ CSS assets load successfully"
+          else
+            echo "❌ CSS assets failed to load"
+            exit 1
+          fi
+          
+          # Cleanup
+          docker stop $CONTAINER_ID
+          docker rm $CONTAINER_ID
+          
+          echo "✅ All container tests passed"
+
+  check-files:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Check required files exist
+        run: |
+          REQUIRED_FILES=(
+            "karaoke.karaniwan.org/index.html"
+            "karaoke.karaniwan.org/songs.html"
+            "karaoke.karaniwan.org/assets/application-b504973bc673ef9f09352588c7d791495f9fa7b652e6bf0d71ea86a094aa4007.css"
+            "Dockerfile"
+            "nginx.conf"
+            ".dockerignore"
+          )
+          
+          MISSING_FILES=()
+          for file in "${REQUIRED_FILES[@]}"; do
+            if [ -f "$file" ]; then
+              echo "✅ $file exists"
+            else
+              echo "❌ $file is missing"
+              MISSING_FILES+=("$file")
+            fi
+          done
+          
+          if [ ${#MISSING_FILES[@]} -gt 0 ]; then
+            echo ""
+            echo "❌ Missing required files:"
+            printf '  - %s\n' "${MISSING_FILES[@]}"
+            exit 1
+          fi
+          
+          echo ""
+          echo "✅ All required files present"
+
+      - name: Check for HTTrack artifacts in content
+        run: |
+          echo "Checking that HTTrack artifacts are not included in Docker context..."
+          
+          # These should be in .dockerignore
+          if [ -d "hts-cache" ]; then
+            if grep -q "hts-cache" .dockerignore; then
+              echo "✅ hts-cache/ directory excluded in .dockerignore"
+            else
+              echo "❌ hts-cache/ should be in .dockerignore"
+              exit 1
+            fi
+          fi
+          
+          echo "✅ HTTrack artifacts properly excluded"

.github/copilot-instructions.md

@@ -76,13 +76,31 @@ docker tag karaokepedia:latest your-registry/karaokepedia:latest
 docker push your-registry/karaokepedia:latest
 ```
 
-### CI/CD Pipeline (Gitea Actions)
+### CI/CD Pipelines (Gitea Actions)
+
+#### Build & Deploy (`.gitea/workflows/build.yml`)
 - **Trigger**: Push to `main` branch or manual dispatch
-- **Workflow**: `.gitea/workflows/build.yml` (GitHub Actions-compatible syntax)
 - **Steps**: Checkout → Setup Buildx → Login to registry → Build & push → Output digest
 - **Tags**: `:latest` and `:main-<commit-sha>`
 - **Registry**: Configure via secrets (DOCKER_USERNAME/DOCKER_PASSWORD for Docker Hub, or adapt for Gitea registry)
 
+#### PR Validation (`.gitea/workflows/pr-validation.yml`)
+- **Trigger**: Pull request opened, edited, synchronized, or reopened
+- **Jobs**:
+  - `validate-pr-title`: Enforces [Conventional Commits](https://www.conventionalcommits.org/) format
+  - `validate-docker`: Checks Dockerfile, nginx.conf, and .dockerignore syntax
+  - `build-test`: Builds image and tests container starts, pages load, assets accessible
+  - `check-files`: Verifies required files exist, HTTrack artifacts excluded
+
+**Conventional Commit Types**: `feat`, `fix`, `docs`, `style`, `refactor`, `perf`, `test`, `chore`, `ci`, `build`, `revert`
+
+**Example PR titles**:
+- ✅ `feat: add user authentication`
+- ✅ `fix(docker): correct nginx config path`
+- ✅ `docs: update README with deployment steps`
+- ❌ `Added new feature` (missing type)
+- ❌ `Update files` (not descriptive)
+
 ### Registry Configuration
 Edit `.gitea/workflows/build.yml` and uncomment the appropriate registry:
 - **Docker Hub** (default): Uses `DOCKER_USERNAME` and `DOCKER_PASSWORD` secrets