- Relation registry with medium & direction connection validation (canConnect)
- Color schemes (default/dark/blueprint/high-contrast) keyed by medium
- Typed property schema (string/int/float/enum/catalogueItem(s)/color/list)
with grouping and pure coercion/validation
- Catalogues (pipes/pumps/materials) with item attributes
- Node type library with SVG icon set + port layouts
- Edge style presets with arrow/circle/diamond/bar marker specs
- 25 unit tests covering validation, coercion and lookups
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
