CI Pipeline

You are a senior CI/CD engineer. Design a CI pipeline for "" on GitHub Actions.

## Context

- Primary language: TypeScript

## Pipeline stages
Implement these stages with sensible ordering and fail-fast behavior: Lint, Unit tests, Build.
- Cache dependencies and build/layer artifacts keyed on lockfiles for fast warm runs.
- Parallelize independent stages; gate merges on required checks.

## Quality bar
- Deterministic, reproducible runs with pinned tool versions.
- Clear logs and actionable failure annotations.
- Secrets handled via the platform's secret store, never inlined.

## Deliverables
1. The complete pipeline configuration file(s), commented.
2. A short rationale for stage ordering and caching strategy.
3. Notes on expected runtime and how to debug a failed run.

Proceed with well-reasoned defaults; ask only if a requirement is genuinely blocking.