Write a GitHub Actions CI/CD Pipeline

Write a GitHub Actions workflow for the following project:

Project type: [e.g. Node.js web app / Python service / Go binary / Docker container]
Deployment target: [e.g. Vercel / AWS EC2 / Railway / Fly.io / Kubernetes / VPS via SSH]
Trigger: [on push to main / on pull request / on tag / scheduled]
Test framework: [e.g. Jest / pytest / go test]
Required checks before deploy: [e.g. tests pass / lint clean / type check / security scan]

Write the complete workflow YAML with:
1. Trigger configuration
2. Jobs structure (separate jobs for test, build, deploy)
3. Caching (node_modules / pip / go modules — whichever applies)
4. Environment variables and secrets handling
5. Test job: install, lint, type check, run tests with coverage
6. Build job: only runs if tests pass
7. Deploy job: only runs on main branch after successful build
8. Deployment steps specific to the target platform
9. Notification on failure (Slack or email — show the structure)
10. Branch protection rules to set (document in comments)