Add a data-retention and account-deletion policy + implementation

[Codex723]

Summary

Design and implement a user-initiated account deletion flow (or documented manual process) compliant with typical data-protection expectations for a fintech app.

Difficulty

Advanced — estimated effort: ~3-7 days (may need discussion before starting). Labels: backend, security, design, advanced

Where to Work

• See relevant files referenced in the description above.

How to Approach This

1. Locate the relevant file(s) below under src/app/api/ or src/lib/.
2. Check src/lib/api-response.ts and follow its existing success/error response shape — don't invent a new one.
3. If you're touching validation, add/extend a Zod schema in src/lib/validations.ts rather than validating inline.
4. If the change affects the database, check prisma/schema.prisma first and run npx prisma generate after any schema edit.
5. Add or update tests near the affected route/lib file (create a __tests__ folder alongside it if one doesn't exist yet, matching the project's existing test conventions).
6. Manually verify with npm run dev and a tool like curl or Postman/Insomnia against the affected endpoint before opening a PR.

Acceptance Criteria

• Behavior described above is implemented in the file(s) listed under "Files Likely Affected".
• Response shape follows the existing convention in src/lib/api-response.ts.
• Input validation (if applicable) is added via src/lib/validations.ts, not inline.
• Tests added/updated covering both the happy path and at least one failure/edge case.
• Manually verified against a running local server (npm run dev).
• No new TypeScript or lint errors (npm run lint, tsc --noEmit).

Notes for Contributors

Comment on this issue before starting so it can be assigned to you and duplicate work is avoided. If the described approach doesn't quite fit once you're in the code (e.g. the file has moved, or there's a cleaner way to do it), that's fine — leave a comment explaining the deviation in your PR description rather than silently changing scope.

[OmniZlatoon]

📋 Grainlify Application

@OmniZlatoon has applied to work on this issue as part of the Grainlify program.

I CAN DELIVER MAINTAINER! PLEASE ASSIGN AND SEE IT WORK

Hi maintainer sir, I'm called Junior Brown , a full-stack and smart contract engineer building on Stellar. I specialize in designing and shipping scalable, secure systems end-to-end, from Soroban smart contracts to production-ready backend infrastructure and user-facing applications.

I’ve worked on complex architectures involving automated agents, cross-chain logic, and data indexing, focusing on reliability, performance, and clean standards. My approach is very product-driven: I don’t just build contracts, I build complete systems that solve real user problems and can scale in production.

I’m especially interested in infrastructure, security, and automation creating tools and frameworks that make it easier for other developers to build safely and efficiently on Stellar.

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