[32] Add GitHub Actions CI for StepFi-API

[EmeditWeb]

Problem

The StepFi-API repo has no GitHub Actions workflow. PRs can merge with broken TypeScript builds or failing tests because nothing enforces them.

Context

Open-source contributors will submit PRs blind. CI is the gate that prevents broken builds from landing in main. Without it, the maintainer has to manually run npm run build on every PR.

Before Starting

Read these context files first:

• context/architecture-context.md
• context/code-standards.md
• context/progress-tracker.md

What To Build

1. Create .github/workflows/ci.yml.
2. Triggers: pull_request to main + push to main.
3. Job build-test: ubuntu-latest, Node 20 via actions/setup-node@v4 with cache: 'npm'.
4. Steps: checkout → setup node → npm ci → npm run build → npm test.
5. Cache node_modules keyed on package-lock.json hash.
6. Add CI status badge to README pointing at the workflow.

Files To Touch

• .github/workflows/ci.yml
• README.md

Acceptance Criteria

• Workflow runs on every PR to main
• Failing build blocks merge
• node_modules cached between runs
• Total run time under 5 minutes
• Status badge visible at top of README
• No secrets exposed in workflow logs

Mandatory Checks Before PR

• CI passes on a test PR before merging
• Zero secrets committed to the repo
• context/progress-tracker.md updated

[Swayymalcolm99]

Hello maintainer, can I take this on?

[Adeyemi-cmd]

Hello maintainer. i would love to work on this

[grantfox-oss]

🦊 GrantFox — @Adeyemi-cmd has been assigned to this issue as part of the Official Campaign campaign!

Next steps:

1. Open a Pull Request referencing this issue (e.g., Closes #16)
2. Your PR will be reviewed by the StepFi-app maintainers

Good luck! Track your progress on GrantFox.

[grantfox-oss]

🎉 This issue has been marked as completed on GrantFox as part of the Official Campaign campaign!

@Adeyemi-cmd's PR #42 was approved and merged by @EmeditWeb.

🏆 @Adeyemi-cmd: You earned 35 FoxPoints for this contribution! Your current tier: Explorer (83 total points). Track your full progress on GrantFox.

👏 Great work, @Adeyemi-cmd! Keep contributing to StepFi-app.