feat(frontend): Implement SSR OG metadata caching with revalidation

[Viky207]

Problem

og-metadata.ts fetches on every SSR request.

Task

Cache OG metadata.

Acceptance Criteria

• Cache in Redis with 60s TTL
• Revalidation on payment-link.updated
• Stale fallback if backend down
• Cache key: og:{username}:{amount}:{asset}
• Cache-Control: s-maxage=60, stale-while-revalidate
• Vercel Edge Cache used

[natho080]

@natho080 has applied to work on this issue as part of the Stellar Wave Program's 8th wave.

Hi! I’d like to contribute by working on this issue. I’ve gone through the description and would like to investigate the current behavior and determine the best approach for addressing it. I’ll keep the implementation focused and make sure the changes are properly tested before opening a PR.

ℹ️ Repo Maintainers: To accept this application, review their application or assign @natho080 to this issue.

[Zinai10]

@Zinai10 has applied to work on this issue as part of the Stellar Wave Program's 8th wave.

Hey maintainer! i would like to work on this issue

ℹ️ Repo Maintainers: To accept this application, review their application or assign @Zinai10 to this issue.

[drips-wave]

Congratulations, @Zinai10! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on August 31, 2026.

🧑‍💻 @Zinai10: 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 🌊