Kaptein view-model: the renderer-agnostic domain layer (the product).
This crate owns all semantics — columns, sorting, filtering, status inference, permission decisions, and action graphs. The frontends (TUI, GUI, headless, serve) consume the render contract defined here and own only geometry.
See ADR-0005 (docs/adr/0005-render-intent-three-layers.md) for the three-layer
model this crate implements.