🤖 feat: implement trunk-based CI/CD with local testing

- Designed trunk-based development workflow with branch protection
- Added workflow validation job to prevent main branch breaks
- Integrated act (GitHub Actions runner) for local Gitea workflow testing
- Created unified CI/CD script interface (scripts/cicd.sh)
- Added YAML lint configuration with practical limits (400 chars)
- Organized all CI/CD scripts under scripts/cicd/ directory
- Confirmed Gitea/GitHub Actions compatibility via local testing
- Updated ADR 0017 with implementation details and test results
- Enhanced documentation with local development workflow

See ADR-0017 for complete trunk-based development workflow documentation.
See ADR-0016 for CI/CD pipeline design.

scripts/cicd/test-cicd-docker.sh

@@ -0,0 +1,99 @@
+#!/bin/bash
+# Comprehensive Docker-based CI/CD testing script
+# Tests workflows locally using Docker containers
+
+set -e
+
+echo "🐳 Docker-based CI/CD Testing"
+echo "================================"
+
+# 1. Check Docker is available
+if ! command -v docker >/dev/null 2>&1; then
+    echo "❌ Docker not found. Please install Docker first."
+    echo "   https://docs.docker.com/get-docker/"
+    exit 1
+fi
+
+echo "✅ Docker is available"
+
+# 2. Pull required images
+echo ""
+echo "📦 Pulling Docker images..."
+docker pull gitea/act_runner:latest
+docker pull pipelinecomponents/yamllint:latest
+docker pull mikefarah/yq:latest
+
+echo "✅ Images pulled successfully"
+
+# 3. Validate YAML syntax with yq
+echo ""
+echo "🔍 Validating YAML syntax..."
+docker run --rm \
+    -v $(pwd):/workspace \
+    -w /workspace \
+    mikefarah/yq:latest \
+    yq eval .gitea/workflows/ci-cd.yaml > /dev/null 2>&1
+
+if [ $? -eq 0 ]; then
+    echo "✅ YAML syntax is valid"
+else
+    echo "❌ YAML syntax error"
+    docker run --rm \
+        -v $(pwd):/workspace \
+        -w /workspace \
+        mikefarah/yq:latest \
+        yq eval .gitea/workflows/ci-cd.yaml || true
+    exit 1
+fi
+
+# 4. Lint YAML with yamllint
+echo ""
+echo "🧹 Linting YAML..."
+docker run --rm \
+    -v $(pwd):/workspace \
+    -w /workspace \
+    pipelinecomponents/yamllint:latest \
+    yamllint .gitea/workflows/
+
+if [ $? -eq 0 ]; then
+    echo "✅ YAML linting passed"
+else
+    echo "❌ YAML linting failed"
+    exit 1
+fi
+
+# 5. Run workflow with act
+echo ""
+echo "🚀 Running CI/CD workflow..."
+docker run --rm \
+    -v $(pwd):/workspace \
+    -w /workspace \
+    -e GITEA_INTERNAL="https://gitea.arcodange.lab/" \
+    -e GITEA_EXTERNAL="https://gitea.arcodange.fr/" \
+    -e GITEA_ORG="arcodange" \
+    -e GITEA_REPO="DanceLessonsCoach" \
+    gitea/act_runner:latest \
+    act -W .gitea/workflows/ci-cd.yaml --rm
+
+if [ $? -eq 0 ]; then
+    echo "✅ Workflow executed successfully"
+else
+    echo "❌ Workflow execution failed"
+    exit 1
+fi
+
+echo ""
+echo "🎉 All CI/CD tests passed!"
+echo "================================"
+echo "📁 Workflow: .gitea/workflows/ci-cd.yaml"
+echo "✅ YAML syntax validated"
+echo "✅ YAML linting passed"
+echo "✅ Workflow execution successful"
+echo "🎯 Ready for production deployment"
+
+echo ""
+echo "💡 Next Steps:"
+echo "  1. Commit changes: git commit -m '🤖 ci: update workflow'"
+echo "  2. Push to trigger: git push origin main"
+echo "  3. Monitor pipeline: https://gitea.arcodange.lab/arcodange/DanceLessonsCoach/actions"
+echo "  4. Check badges: https://gitea.arcodange.fr/arcodange/DanceLessonsCoach"