Permify integration

Permify is a Zanzibar-style authorization service: an authorization model written in the Permify schema language defines entities, relations, permissions and attribute rules, and relationship tuples plus attributes stored per tenant answer access questions against it. This catalog entry lets an agent create, list and delete tenants, write a schema and read it back, apply a partial schema change without resending the whole model, list the schema versions a tenant holds, write and delete relationship tuples and attributes, read tuples and attributes back with a filter, ask whether a subject holds a permission on an entity, ask a batch of those questions in one call, expand a permission into the tree of relations that grant it, look up every entity of a type a subject may act on, look up every subject that may act on an entity, list all permissions one subject holds on one entity, and manage reusable data bundles: write, read, delete and run one against supplied arguments. The streaming legs are absent because they hold the connection open and emit results as they are found rather than answering once. The host is part of the credential because every install is its own deployment: point it at the Permify HTTP listener (port 3476 by default). Authentication is the server's pre-shared key, or an OIDC access token when the server is configured for one, sent as a bearer token in the Authorization header; a server started without authentication accepts any placeholder value.