[Backend] Middleware: Implement Rate Limiting and Security Guards

[ONEONUORA]

Description

Protect the Axum server from DDoS, brute force, and abuse:

• Implement rate limiting middleware (e.g. using tower-limit or Redis rate limiter).
• Setup CORS parameters strictly.
• Set secure HTTP headers (HSTS, CSP, X-Frame-Options) via tower-http.

Acceptance Criteria

• Limit requests per IP address.
• Reject requests exceeding limits with 429 Too Many Requests.
• Tests to check that rate limits trigger under heavy mock traffic.

[karanjadavi]

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

can i work on this issue ?

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

[drips-wave]

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

🧑‍💻 @karanjadavi: 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 🌊

[grantfox-oss]

🎉 This issue has been marked as completed on GrantFox!

@karanjadavi's PR #870 was approved and merged by @ONEONUORA.

🏆 @karanjadavi: You earned 35 FoxPoints for this contribution! Your current tier: Explorer (191 total points). Track your full progress on GrantFox.

👏 Great work, @karanjadavi! Keep contributing to Fracverse.