pi.provider / baseUrl / model / thinkingLevel / apiKeySecretRef are now DEPRECATED_SETTINGS_FIELDS: kept in the schema for stored JSON, dropped from PATCH /settings and from the settings sections, never read by the server. runAgent fails with a clear message when no upstream is set. The agent demo gate checks the default upstream provider; e2e seeds a fake upstream as default. OpenAPI summaries say Agent upstream. Co-Authored-By: Claude Opus 5.5 <[email protected]>