Browse the provider for a source scope

A shallow listing fetched through the stored credential: Drive folders, or the Notion pages and databases the integration was granted. This route exists so a client can present a scope picker WITHOUT ever holding a provider token — the response contains no credential material of any kind.

Requires the connectors:write scope. Accepts all three lanes: a session JWT (bounded by the caller's role on this workspace) or an il_* machine credential whose own scope set, workspace set and validity window cover it — both ceilings apply and neither can raise the other, so a credential carrying connectors:write is still refused where the role does not permit it.

A credential with no scope record resolves to LEGACY_DEFAULT, which does NOT include connectors:write — mint a key with it explicitly (POST /v2/workspaces/{id}/keys).