Contracts docs: Frontend type contracts for API responses

[codebestia]

Write apps/web/docs/contracts-response-types.md documenting the TypeScript types the frontend uses to model backend REST/WS responses, and how well they currently track the backend's actual Zod schemas.

Acceptance criteria:

• Every response type used by the frontend is documented alongside the backend schema it's meant to correspond to
• Any drift found between a frontend type and the actual backend response shape is called out explicitly as a known discrepancy — file it as a follow-up rather than fixing it here

[Jenks00]

@Jenks00 has applied to work on this issue as part of the Stellar Wave Program's 7th wave.

Hi maintainer I would like to work on this issue please assign it to me

ℹ️ Repo Maintainers: To accept this application, review their application or assign @Jenks00 to this issue.

[drips-wave]

Congratulations, @Jenks00! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on July 30, 2026.

🧑‍💻 @Jenks00: 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 🌊