Add ContractMonitor MTTR and MTBF derived metrics with rolling windows

[greatest0fallt1me]

Description

monitoring.rs records incidents but exposes only counts. Compute and surface rolling Mean Time To Recovery and Mean Time Between Failures over a configurable window so operators can spot deteriorating reliability before it triggers the circuit breaker.

Requirements and Context

• Add RollingWindow { capacity: u32 } ring buffer
• Compute MTTR/MTBF in seconds as i128
• Window writes are bounded and replace oldest entries
• Must be secure, tested, and documented
• Should be efficient and easy to review

Suggested Execution

1. Fork the repo and create a branch

   git checkout -b feature/monitoring-mttr-mtbf

2. Implement changes
   • contracts/predictify-hybrid/src/monitoring.rs
   • contracts/predictify-hybrid/src/tests/monitoring_mttr_tests.rs
3. Test and commit
   • cargo test -p predictify-hybrid mttr_mtbf
   • Cover edge cases
   • Include test output and notes in the PR

Example commit message

feat: expose rolling MTTR and MTBF metrics from ContractMonitor

Acceptance Criteria

• MTTR/MTBF queryable through view functions
• Window capacity is admin-configurable within sane bounds
• Property test: averages match brute-force on small windows

Guidelines

• No unwrap() in production paths
• Clear documentation and inline comments
• Timeframe: 96 hours

[ayaoba24]

@ayaoba24 has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

Please assign. I can fix this

ℹ️ Repo Maintainers: To accept this application, review their application or assign @ayaoba24 to this issue.

[drips-wave]

Congratulations, @ayaoba24! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on June 30, 2026.

🧑‍💻 @ayaoba24: 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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