feat(versioning) : add entity versioning with numbered versions and restore

Backend:
- Migration: version column on audit_logs and machines
- AuditLog, Machine, Composant, Piece, Product: version + skipAudit properties
- AbstractAuditSubscriber: auto-increment version, skip on restore, fix decimal diff
- Enriched snapshots with slots, custom fields and version number
- AuditLogRepository: findVersionHistory, findByVersion
- EntityVersionService: list, preview, restore with skeleton/integrity checks
- EntityVersionController: REST endpoints for all 4 entity types
- 11 tests covering list, preview, restore, auth

Frontend: update submodule pointer

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/EventSubscriber/MachineAuditSubscriber.php

@@ -36,13 +36,25 @@ final class MachineAuditSubscriber extends AbstractAuditSubscriber
 
     protected function snapshotEntity(object $entity): array
     {
+        $customFieldValues = [];
+        foreach ($entity->getCustomFieldValues() as $cfv) {
+            $customFieldValues[] = [
+                'id'        => $cfv->getId(),
+                'fieldName' => $cfv->getCustomField()?->getName(),
+                'fieldId'   => $cfv->getCustomField()?->getId(),
+                'value'     => $cfv->getValue(),
+            ];
+        }
+
         return [
-            'id'              => $entity->getId(),
-            'name'            => $this->safeGet($entity, 'getName'),
-            'reference'       => $this->safeGet($entity, 'getReference'),
-            'prix'            => $this->safeGet($entity, 'getPrix'),
-            'site'            => $this->normalizeValue($this->safeGet($entity, 'getSite')),
-            'constructeurIds' => $this->normalizeCollection($entity->getConstructeurs()),
+            'id'                => $entity->getId(),
+            'name'              => $this->safeGet($entity, 'getName'),
+            'reference'         => $this->safeGet($entity, 'getReference'),
+            'prix'              => $this->safeGet($entity, 'getPrix'),
+            'site'              => $this->normalizeValue($this->safeGet($entity, 'getSite')),
+            'constructeurIds'   => $this->normalizeCollection($entity->getConstructeurs()),
+            'customFieldValues' => $customFieldValues,
+            'version'           => $this->safeGet($entity, 'getVersion'),
         ];
     }
 }