feat: Add CI/CD secrets configuration and documentation

- Add comprehensive CI/CD secrets section to .env.example
- Create detailed CI-CD-SECRETS.md guide with:
  - Step-by-step secret setup instructions
  - Container registry authentication examples
  - PyPI token configuration
  - GitHub integration setup
  - Security best practices
  - Troubleshooting guide
  - Workflow-specific requirements

Includes support for:
- Docker Hub, GitLab, GitHub container registries
- Automated PyPI publishing
- Slack/Discord notifications
- Kubernetes deployment secrets
- Security scanning integration

Updated .env template with placeholder values and detailed comments.

docs/ci-cd/local-testing.md

@@ -0,0 +1,58 @@
+# Local CI/CD Testing
+
+This guide helps you test CI/CD workflows locally before pushing to the repository.
+
+## Prerequisites
+
+- Docker with Buildx support
+- uv package manager
+- Python 3.8+
+
+## Local Testing Commands
+
+```bash
+# Test local build
+make docker-build
+
+# Test multi-arch build
+make docker-buildx-local
+
+# Test full development workflow
+make dev
+
+# Run health checks
+./scripts/health_check.sh
+```
+
+## Workflow Testing
+
+Use `act` to test GitHub/Gitea workflows locally:
+
+```bash
+# Install act
+curl https://raw.githubusercontent.com/nektos/act/master/install.sh | sudo bash
+
+# Test PR workflow
+act pull_request -s CONTAINER_REGISTRY_USERNAME=test -s CONTAINER_REGISTRY_PASSWORD=test
+
+# Test release workflow
+act push -e tests/fixtures/release-event.json
+```
+
+## Troubleshooting
+
+### Build Issues
+- Ensure all vendor assets are committed
+- Check Docker daemon is running
+- Verify buildx is properly configured
+
+### Registry Issues
+- Check .env file configuration
+- Verify registry credentials
+- Test registry connectivity
+
+### Performance Issues
+- Use build cache: `--cache-from type=gha`
+- Optimize Docker layers
+- Use multi-stage builds
+```