Close #16

PR description:

Summary

Adds a CI pipeline to enforce TypeScript builds and tests on every PR to main and every push to main.

Changes

• .github/workflows/ci.yml — New workflow with a single build-test job:
  • Triggers: push and pull_request to main
  • Runs on ubuntu-latest with Node 20 (actions/setup-node@v4, cache: 'npm')
  • Explicit node_modules cache keyed on package-lock.json hash via actions/cache@v4
  • Steps: checkout → setup-node → npm ci → npm run build → npm test
  • Concurrency group cancels stale in-flight runs
  • Minimal contents: read permission (no secrets exposed)
• README.md — Added CI status badge linking to the workflow
• context/progress-tracker.md — Updated with CI pipeline completion entry