The AgentOptions.systemPrompt doc said the persona 'may reference'
variables without saying that every complete {{...}} group IS interpreted,
strictly, and that literal {{...}} prose has no escape syntax yet (the
RFC's recorded deferral). A persona author reads this line first; it now
carries the contract. (ds-review-bot inline finding: the escape mechanism
itself stays deferred per the RFC — pre-release, no external consumers,
and the failure is loud with the fix in the message.)
2f191cc72b