Structured Logging & Prometheus Metrics Export

[N-i-xx]

Description

Implementation work for: Structured Logging & Prometheus Metrics Export, within the vero-audit-guard observational monitoring layer.

Problem Statement

There is no standardized way to observe queue depth, confirmation rate, write latency, or reload status in production.

Proposed Changes

• Implement core logic per the target module described above
• Add error propagation via the 'thiserror' crate rather than bare panics
• Add regression tests covering non-happy-path and adversarial-input scenarios
• Wire telemetry/logging so failures surface as alerts, not silent drops

Technical Implementation Scaffolding

• Target Repository: vero-audit-guard
• Target Path: src/audit-guard/
• Branch Naming: security/issue-VAG-013-structured-logging-prometheus-metrics-export
• Authority Context: Observational/telemetry-only — no on-chain halt authority

Acceptance Criteria

• Logic adheres to observational-only invariant
• Unit tests demonstrate >80% code coverage
• CI/CD pipeline confirms successful build and linting

Security & Audit Considerations

• Reviewed for ZK-readiness, memory safety, and signing/key-handling correctness where applicable

Definition of Done

• Code reviewed by lead maintainer
• Pull request merged via verified status check

[Okorie2000-code]

Hi Maintainer,
I’d like to work on this issue. I understand the observability requirements and will implement structured logging, Prometheus metrics, proper error handling, and test coverage improvements. Kindly assign.

[Joyful12-tech]

Hello Maintainer,

I'd like to work on this issue. I'll implement structured logging and Prometheus metrics export, add the required tests, and submit a PR within 2 days.
Thank you!

[akinboyewaSamson]

Hello,

I’m a smart contract and full-stack developer interested in contributing to this issue.

I have experience contributing through OnlyDust and have participated in Drips Wave 4, Wave 5, Wave 6, as well as the GrantFox beta campaign.

My technical background includes Rust, Soroban, Cairo, Solidity, and TypeScript, with a focus on building secure, scalable, and maintainable blockchain applications.

Based on the scope of this issue, I’m confident I can deliver a complete and well-tested solution within 10hours of assignment. I prioritize clean code, clear documentation, and efficient implementation.

I’d appreciate the opportunity to contribute and help move this issue forward.

Thank you.

[BigManly4]

Hi maintainer, I would love to resolve this issue within few hours. I am a Full-Stack Dev with contributions to Oss projects. Please assign. Thank you

[missmatty234]

Hi Maintainer, I’d love to work on this issue. I have experience across the full stack and DevOps lifecycle, and I’m confident I can deliver according to the requirements. Kindly assign it to me.

[grantfox-oss]

🦊 GrantFox — @akinboyewaSamson has been assigned to this issue as part of the Official Campaign | FWC26 campaign!

Next steps:

1. Open a Pull Request referencing this issue (e.g., Closes #181)
2. Your PR will be reviewed by the Vero-protocol maintainers

Good luck! Track your progress on GrantFox.