Sandbox and verification

Use the product setup journey to prove a server-side decide call without changing UI.

Publisher setup issues a long-lived serving key and a coding-agent prompt. A test decide call during verification can return a deterministic test offer when the envelope has usable context. Treat that like any other serve: render only on an existing surface.

Fail-open still applies. A missing key, timeout, or serve:false must not block the organic answer. Do not build an API console against unpublished fixture runners.