PayPal client_secret (and any secret-named integration field) was stored
plaintext in integrations.config, unlike Stripe/door which use the
AES-256-GCM vault. A DB read or backup leaked it in cleartext.
- lib/secrets/vault.ts: canonical generic storeSecret/readSecret +
isSecretConfigField (the proven Stripe vault logic, generalized).
- saveIntegration: secret-named fields go to the vault, only a *_ref is
kept in config; blank submit preserves the ref (write-only like
Stripe); legacy plaintext auto-migrates into the vault on next save.
- paypal/sync reads client_secret from the vault, transitional fallback
to legacy plaintext until the next save.
- Docs updated (API_REFERENCE, ARCHITECTURE 10.3). 502 tests.
PayPal sync route now returns the inserted rows; the client prepends
them (mirrors handleLogCash) instead of window.location.reload(),
preserving scroll/filter state. Was the only full reload in the app.
payments has no unique index on external_id, so the
onConflict:'external_id' upsert was unreliable and fell back to an
insert that stripped external_id -- creating duplicate, non-idempotent
rows on every re-sync, and not tenant-scoped. Now: look up which PayPal
transaction ids already exist in THIS space and insert only the new
rows (external_id preserved). No schema change.