[CI/CD] Ephemeral PR preview environments with Hardhat fork

[nanaf6203-bit]

Problem Statement

PRs are validated against shared testnets. There's no per-PR isolated environment for full-stack integration.

Acceptance Criteria

• A "preview environment" workflow uses Vercel previews for the frontend and a Hardhat fork node for the backend
• GitHub PR bot posts the URL automatically
• Environment destroyed when PR closes

Implementation Notes

Vercel webhook → GitHub Action → ephemeral fork. Use wagmi http://preview-fork:8545.

Files Likely Affected

• .github/workflows/preview.yml
• src/config/wagmi.ts
• docs/preview.md

Difficulty / Effort

• Difficulty: Hard
• Effort: T-Shirt XL

Labels

ci-cd, priority:low, area:infrastructure, area:web3

[acmenoch1]

@acmenoch1 has applied to work on this issue as part of the Stellar Wave Program's 7th wave.

Hello Maintainer, i would like to work on this issue, please assign me.

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[oladev2026-tech]

@oladev2026-tech has applied to work on this issue as part of the Stellar Wave Program's 7th wave.

Hi can i work on this task? Kindly assign

ℹ️ Repo Maintainers: To accept this application, review their application or assign @oladev2026-tech to this issue.

[drips-wave]

Congratulations, @oladev2026-tech! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on July 30, 2026.

🧑‍💻 @oladev2026-tech: 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.

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