This looks really slick! I was building something similar, so visuals are re-useable artifacts that external services know how to render, where we ask agents in whatever the interface is, slack, team's other agentic harnesses etc. and the agents receive the spec from the service, in this case dbt charts. if there was a unified spec that was agreed upon these third-party harnesses and apps would all speak the same charting language which would be super cool. I haven't read through it in detail but how does this differ from something like https://github.com/vega/vega-lite