Security Hardening for Backend Transaction Proxy

[Emmzyemms]

Description:
Add input validation, amount limits, and anti-spam measures to transaction endpoints.
Labels: security, backend

[dayo-dev17]

@dayo-dev17 has applied to work on this issue as part of the Stellar Wave Program's 5th wave.

Hi Maintainer, I would love to work on this issue. I'm a backend developer with experience working within the stellar ecosystem. This should be an easy fix

ℹ️ Repo Maintainers: To accept this application, review their application or assign @dayo-dev17 to this issue.

[drips-wave]

Congratulations, @dayo-dev17! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on June 2, 2026.

🧑‍💻 @dayo-dev17: 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

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