Add health response uptime and ISO timestamp metadata

[emrekayat]

Goal

Make the public health endpoint more useful for operators and demos by returning basic runtime metadata.

Scope

• Update the API health response to include an ISO timestamp and process uptime seconds.
• Keep existing health fields and status behavior unchanged.
• Avoid exposing secrets, environment variables, wallet addresses, or host internals.
• Update the focused public route test.

Acceptance criteria

• GET /health includes timestamp as a valid ISO string.
• GET /health includes uptimeSeconds as a non-negative number.
• Existing health metadata still appears.
• npm test --workspace @query402/api -- src/routes/public.test.ts passes.
• npm run typecheck --workspace @query402/api passes.

Notes

This should be a small API-only change with one focused test update.

[fwseyi]

@fwseyi has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

I will update the GET /health endpoint to return the current system time as an ISO string (timestamp) and the process runtime in seconds (uptimeSeconds). These new fields will complement the existing health checks without exposing sensitive system properties or altering current status behaviors. Finally, I will update the focused public route tests and verify the changes by running npm test --workspace @query402/api -- src/routes/public.test.ts and npm run typecheck.

ℹ️ Repo Maintainers: To accept this application, review their application or assign @fwseyi to this issue.

[drips-wave]

Congratulations, @fwseyi! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on June 30, 2026.

🧑‍💻 @fwseyi: Please resolve the issue such that the repo's maintainers have enough time to review your contribution before the due date. You'll earn Points for completing the issue on-time, which will make you eligible for a share of the Stellar Wave Program's reward pool.

Warning

When opening a PR, please link it to this issue to ensure it gets tracked accurately. Points are awarded when this issue is marked as completed by the maintainer.

🤠 Repo maintainers: Please keep an eye on the contributor's progress and review their work before the due date. You can manage this issue, including adjusting its complexity and points, here.

🌊 Happy Wave 🌊