[P1][backend] Add account lockout and credential-stuffing defenses

[dzekojohn4]

Track failed authentication safely, add progressive delays or limits, and provide recovery without account enumeration.

[chemicalcommando]

@chemicalcommando has applied to work on this issue as part of the Stellar Wave Program's 8th wave.

Hello, I'm interested in taking this issue on.

I'll implement this following the existing conventions in the codebase, with tests covering the new behavior.

I'd appreciate being assigned to this issue and look forward to contributing.

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

[sanctus-mvp]

@sanctus-mvp has applied to work on this issue as part of the Stellar Wave Program's 8th wave.

I will love to work on this issue please. I deliver high impact solutions, ensuring seamless workflow and client satisfaction

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[Jumongweb]

@Jumongweb has applied to work on this issue as part of the Stellar Wave Program's 8th wave.

Hi maintianer, i will like to solve this issue

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[Gracora]

@Gracora has applied to work on this issue as part of the Stellar Wave Program's 8th wave.

I'd like to add robust account lockout and credential-stuffing defenses to the backend. The core deliverable is safely tracking failed authentication and adding progressive delays or limits while providing recovery that does not leak account existence. My approach is to store failed attempts with backoff logic, enforce lockout thresholds, and design recovery so enumeration is impossible.

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[drips-wave]

Congratulations, @Gracora! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on August 31, 2026.

🧑‍💻 @Gracora: 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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