Specialists and model profiles

A specialist is a durable child run, not an ambient nested prompt. The parent records the exact specialist identity, typed input, authority boundary, budget, depth, concurrency slot, runtime and model profile digests, and typed result.

Use read-only specialists for analysis whenever mutation is unnecessary. Consequential specialist tools still pass through the same effect and approval interceptors as the parent. Cancellation and budget exhaustion propagate durably; completed child evidence remains readable.

A model profile describes an exact provider/model/transport posture and its bounded capabilities. It does not grant access. Platform, customer, project, placement, privacy, and policy authority are composed separately before admission.