Add response header helper for public endpoints

[Chucks1093]

Summary

Add a shared helper for setting common headers on public endpoints.

Scope

• centralize repeated public response header logic
• keep the helper focused and reusable
• avoid mixing route-specific behavior into it

Acceptance Criteria

• public endpoints can reuse one header helper
• repeated header logic is reduced
• helper remains small and easy to understand

Contributor note: comment on the issue first and reach out in Telegram for updates or coordination: https://t.me/accesslayerorg

[Belzabeem]

@Belzabeem has applied to work on this issue as part of the Stellar Wave Program's 3rd wave.

Hi, I would love to work on this issue

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

[michaelvic123]

@michaelvic123 has applied to work on this issue as part of the Stellar Wave Program's 3rd wave.

please assign me this issue

ℹ️ Repo Maintainers: To accept this application, review their application or assign @michaelvic123 to this issue.

[drips-wave]

Congratulations, @michaelvic123! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on March 30, 2026.

🧑‍💻 @michaelvic123: 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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