feat: auto populate machine structures and seed sample data

prisma/migrations/20250927120000_add_component_structure/migration.sql

@@ -0,0 +1,3 @@
+-- Add JSON column to store instantiated structure selections on components
+ALTER TABLE "composants"
+ADD COLUMN IF NOT EXISTS "structure" JSONB;

prisma/schema.prisma

@@ -84,6 +84,7 @@ model Composant {
   prix      Decimal? @db.Decimal(10, 2)
   createdAt DateTime @default(now())
   updatedAt DateTime @updatedAt
+  structure Json?
 
   typeComposantId String?
   typeComposant   ModelType? @relation("ModelTypeComponentAssignments", fields: [typeComposantId], references: [id])