Make agent's life easier by introducing predefined surfaces.

For wizard-like apps or for status bar or for clients with dashboard, application can communicate predefined surfaces, so that agent does not need to worry about creating these surfaces, it can just update them periodically.

Thus wizards will become 'update-only' apps.

It will make apps less error-prone and more reliable.

Look for existing surface creation and management code in the codebase, likely in core agent or UI modules. Understand how wizards, status bars, and dashboards are currently implemented. The goal is to design a system where these surfaces are predefined and agents can update them, reducing boilerplate and errors.

索引モデルが issue の本文から書いたものです。