Library surfaces
Design References
Contract
Surface components frame or summarize already-projected content.
Panel frames bounded tool regions.
SurfaceCard is for repeated records or grouped
summaries, not page sections. MetricCard is for
compact dashboard numbers.
Surfaces may own spacing, title placement, density, and collapse behavior. They must not own provider semantics, authorization, or product status meaning.
Consequence
Product modules choose content and state labels. Library surfaces make the content scannable without becoming another domain layer.