The ComposantProcessor now reads the structure payload from the frontend
and applies selectedPieceId/selectedProductId/selectedComponentId to the
scaffolded slots, so user selections are actually saved to the database.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
- Add ComposantProcessor: initializes piece/product/subcomponent slots
from ModelType skeleton requirements when a composant is created
- UniqueConstraintSubscriber: priority 256, French error messages,
constraint name detection for specific feedback
- Migration: scaffold missing slots for existing composants in prod
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>