docs(prds): add managed seedbox reseller + BYOS control plane PRD

[ralyodio]

Rewrites the draft against the current BitTorrented stack: CoinPayPortal billing (resolves the generic "CoinPay"), Supabase data model, DigitalOcean provisioning behind a ProvisioningProvider abstraction, and the existing tsx worker pattern. Drops WHMCS in favor of building the control plane natively in the app.

Description

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update
• Refactoring (no functional changes)

Submission Payout

• PR: $100 minimum per accepted PR
• Bug fix: $100 minimum per confirmed bug fix
• QA run: $250 minimum per QA run (files bugs and/or fixes them)
• Feature/fix: $100 minimum per accepted feature implementation or substantive fix

TDD Checklist (MANDATORY)

All items must be checked before merge:

• Tests written FIRST (before implementation)
• All new code has corresponding tests
• All tests pass locally (pnpm test)
• Edge cases are covered
• No any types used (unless explicitly justified)
• TypeScript strict mode passes (pnpm tsc --noEmit)
• ESLint passes (pnpm lint)

Security Checklist

• No Supabase calls from client-side code
• No sensitive data exposed in client bundle
• Input validation implemented
• Rate limiting considered (if applicable)

Testing

Test Coverage

• Number of new tests:
• Test file(s) modified/created:

How to Test

Screenshots (if applicable)

Related Issues

Closes #

Additional Notes

[github-actions]

vu1nz Security Review

0 finding(s) in PR #?

No security issues found.