NovaSupport/pr.md at main · olywales-stack/NovaSupport

What does this PR do?

This PR resolves four backend reliability and security issues (#584 – #587):

#584 — Webhook retry jitter (src/services/webhook.ts): Added ±20 % random jitter to getNextRetryDelay() so retries after a mass failure are spread across a window instead of all firing at the same instant (thundering-herd prevention).
#585 — Canonical webhook signatures (src/services/webhook.ts): Introduced canonicalJsonStringify() — a recursive, alphabetically-key-sorted JSON serialiser — and switched both generateSignature() and the payload body in deliverWebhook() to use it. Subscriber verification is now deterministic regardless of Node version or middleware insertion order.
#586 — Separate recurring-support execution table (prisma/schema.prisma, src/services/drip-scheduler.ts, src/app.ts): Instead of recording a fake txHash = 'pending_…' row in SupportTransaction, the drip scheduler now creates a RecurringSupportExecution row (status: pending). When the user later submits the real Stellar transaction via POST /support-transactions, the endpoint validates the execution details match the subscription and atomically marks it success. This keeps SupportTransaction clean and audit-ready.
#587 — Stellar address as supporterAddress (prisma/schema.prisma, src/app.ts): Added supporterAddress to RecurringSupport and now populate it from req.auth!.walletAddress (the verified Stellar public key), not user.email. Schema is resilient to future email/wallet-address separation.

drip-scheduler.test.ts rewritten to cover the new recurringSupportExecution.create path (6 tests, all pass).
app.test.ts: added Test 42b — integration test for recurringSupportExecutionId validation; corrected URL-normalisation and sanitize-array expectations.
src/middleware/sanitize.ts: fixed javascript: / data: scheme blocking, normalised URLs to always return canonical href (with trailing slash), and enabled HTML sanitization for plain strings inside sanitised arrays.

Closes #584, #585, #586, #587

Webhook jitter: Call getNextRetryDelay(0) (1 s base) multiple times — values will vary within [800 ms, 1 200 ms].
Canonical signatures: Sign a payload with keys in arbitrary order; verify with keys in a different order — HMAC should always match.
Recurring execution flow:
- POST /recurring-support to create a subscription.
- Inspect the drip-scheduler log — no SupportTransaction row is created; a RecurringSupportExecution row with status = pending appears instead.
- POST /support-transactions with recurringSupportExecutionId — mismatched amount/asset/recipient returns 400; matching details succeed and mark the execution success.
Run tests: npm test in backend/ — all tests pass (DB-dependent tests require DATABASE_URL).