SmtpProvider is now scope-aware: it resolves the tenant's own SMTP identity from
the IiosProviderCredential store (providerType SMTP) and sends from it, falling
back to the platform env identity when unset (env fallback applies only to the
platform identity, never a tenant's server). Registered whenever env SMTP OR the
credential store is present; fails closed as NOT_CONFIGURED when neither exists.
Credential endpoints accept SMTP with per-type validation. 18 SMTP tests green.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
IIOS becomes the tenant's integration/credential hub for anything it sends.
New IiosProviderCredential (one row per scope+providerType) seals the secret
with AES-256-GCM under IIOS_CRED_KEY (secret-crypto.ts); only non-secret
displayHints are ever read back. ProviderCredentialService upsert/resolve/status;
TwilioSmsProvider resolves the caller's own creds per scope at send time and
POSTs to Twilio (fail-closed NOT_CONFIGURED when unset). Registered over the
SMS sandbox only when the platform key + store are present. PUT/GET
/v1/providers/:type/credentials (scope-fenced, masked reads). 16 new unit tests.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
maaz519