Define the user-visible Ultra contract

[iam-brain]

Question

What should this plugin promise when a user selects Ultra, and how should that promise differ from selecting max or choosing the existing orchestrator agent?

Resolve with the maintainer, one decision at a time:

• whether Ultra means guaranteed proactive delegation, best-effort proactive delegation, or maximum reasoning with delegation only when the host supports it;
• whether the contract applies in codex mode only or also in native mode;
• whether it applies only to Sol and Terra or to any future catalog-eligible model;
• the canonical display name and description;
• whether the current agent/profile remains selected or Ultra implicitly changes it;
• what users should observe in normal, no-delegation, and failed-delegation scenarios;
• what compatibility claim may be made relative to the open-source Codex CLI and closed-source desktop app.

The resolution becomes the product-level acceptance contract against which architecture, UX, tests, and rollout are judged.