Clone Public Agent

Copy a published agent into the caller's account and start it running.

Copies the brief and the knobs; copies nothing that belongs to the original owner. No findings, no runs, no plan_json — a clone re-plans from the brief on its first run, which is also what keeps a stale cached plan from propagating to every copy.

Two plan clamps instead of two refusals: the cadence steps down to what the cloner can run, and the model tier steps down to what they can fund. The one hard limit is the agent cap, because that is a standing claim on the shared search and inference budget rather than a preference.