test(payments): add HTTP integration tests for payment quote lifecycle (#256)

[ghzhost]

Summary

Closes #256

Adds a comprehensive supertest integration suite (tests/payments-routes.test.ts) exercising the full /api/v1/payments HTTP route lifecycle.

Changes

• POST /api/v1/payments: verified that sending valid input (sourceAsset, destinationAsset, sourceAmount) creates an active quote with status 201 and expected response envelope { success: true, data: { quote: ... } }.
• GET /api/v1/payments/quotes/:id:
  • Live quote returns 200 with quote payload.
  • Non-existent quote returns 404 (Quote not found).
  • Expired quote (>5m TTL) returns 410 (Quote has expired).
• POST /api/v1/payments/execute:
  • Non-existent quote returns 404.
  • Unconfirmed payment (confirmed: false) returns 400 (Payment must be confirmed).
  • Valid execution returns 200 with settled payment record and updates quote status.
  • Repeated execution on already-executed quote returns 409 (Quote has already been executed).
  • Expired quote execution returns 410 (Quote has expired).

Verification

• npx vitest run tests/payments-routes.test.ts tests/payments.schema.test.ts tests/payments.test.ts tests/payments-fee.test.ts passes (41 tests).
• npm run lint, npm run typecheck, and npm run build pass with zero errors.