Get this org’s OAuth app for a connector

Whether connects on this connector use Elaichi’s platform application or one this organization supplied, and the client id if so. The client secret is never returned — has_client_secret reports only whether one is stored. Answers 404 for a connector this organization owns (edit its credentials with PATCH /connector/{slug} instead — the message says so only to a caller who can see it), for a platform remote MCP connector, and for a connector with no OAuth 2.0 credential (auth_formats on GET /connector/{slug} does not include oauth2) unless this organization already has an override stored for it. Every other catalog OAuth 2.0 connector answers 200, whether or not Elaichi’s own app already works for it: oauth_app_mode is platform_default until the organization sets its own, and byoa: true on GET /connector/{slug} is what says the platform has no usable app and one is required. A client reads this endpoint directly: a 404 here means no organization OAuth application applies to this connector and the override UI should not be offered. Requires connector:manage.