Add deep health check endpoint that validates all external dependencies (DB, Stellar RPC, Twilio)

[robertocarlous]

Summary

The current /health endpoint returns a static 200 OK without verifying that external dependencies are actually reachable. Kubernetes liveness/readiness probes pointing at this endpoint will not detect a broken database connection or a Stellar RPC outage.

Proposed Solution

Extend src/routes/health.ts with a GET /health/deep endpoint:

{
  "status": "healthy" | "degraded" | "unhealthy",
  "version": "1.2.3",
  "uptime": 3600,
  "checks": {
    "database": { "status": "healthy", "latencyMs": 4 },
    "stellarRpc": { "status": "healthy", "latencyMs": 120, "ledger": 54321 },
    "twilio": { "status": "healthy", "latencyMs": 89 },
    "agentLoop": { "status": "healthy", "lastTickAt": "2026-06-27T10:00:00Z" }
  }
}

Rules:

• Any unhealthy check → HTTP 503 (K8s marks pod NotReady)
• All degraded but no unhealthy → HTTP 200 with status: degraded
• Deep check protected by internal token to avoid exposing infra details publicly
• Timeout each dependency check at 3s independently

Acceptance Criteria

• GET /health/deep requires internal auth token
• Database check runs a SELECT 1 via Prisma
• Stellar RPC check fetches latest ledger number
• Agent loop check verifies last successful tick was within 2× tick interval
• Returns 503 when any dependency is unhealthy
• K8s deployment.yaml readiness probe updated to use /health/deep
• Unit tests mock each dependency failure independently

[Glam26]

I'd like to take this issue.

I've contributed to similar features in the past, delivering production-ready implementations with a strong focus on maintainability, test coverage, and consistency with existing architecture. I take time to understand the project's patterns before making changes, which helps keep reviews straightforward and minimizes regressions.

I'll provide a clean implementation, comprehensive tests, and clear documentation where applicable, ensuring the final solution integrates seamlessly with the rest of the codebase.

[Glam26]

I'd like to take this issue.

I've contributed to similar features in the past, delivering production-ready implementations with a strong focus on maintainability, test coverage, and consistency with existing architecture. I take time to understand the project's patterns before making changes, which helps keep reviews straightforward and minimizes regressions.

I'll provide a clean implementation, comprehensive tests, and clear documentation where applicable, ensuring the final solution integrates seamlessly with the rest of the codebase.

[Glam26]

I'd like to take this issue.

I've contributed to similar features in the past, delivering production-ready implementations with a strong focus on maintainability, test coverage, and consistency with existing architecture. I take time to understand the project's patterns before making changes, which helps keep reviews straightforward and minimizes regressions.

I'll provide a clean implementation, comprehensive tests, and clear documentation where applicable, ensuring the final solution integrates seamlessly with the rest of the codebase.

[Glam26]

I'd like to take this issue.

I've contributed to similar features in the past, delivering production-ready implementations with a strong focus on maintainability, test coverage, and consistency with existing architecture. I take time to understand the project's patterns before making changes, which helps keep reviews straightforward and minimizes regressions.

I'll provide a clean implementation, comprehensive tests, and clear documentation where applicable, ensuring the final solution integrates seamlessly with the rest of the codebase.

[Glam26]

I'd like to take this issue.

I've contributed to similar features in the past, delivering production-ready implementations with a strong focus on maintainability, test coverage, and consistency with existing architecture. I take time to understand the project's patterns before making changes, which helps keep reviews straightforward and minimizes regressions.

I'll provide a clean implementation, comprehensive tests, and clear documentation where applicable, ensuring the final solution integrates seamlessly with the rest of the codebase.

[gloskull]

Hi, I’d love to work on this issue. I have 4 years of experience across backend, frontend, full-stack, and smart contract development. I understand the task clearly and can deliver a clean, efficient, well-tested solution on time, with strong focus on code quality and maintainability. My PR will be submitted in under 10 hours.

[AugistineCreates]

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

Please assign

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

[drips-wave]

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

🧑‍💻 @AugistineCreates: 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.

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